BEE Paper-1 — Chapter 3: Basics of Energy & Its Forms

1. If wet bulb and dry bulb temperatures read the same, the relative humidity is ____.

1. 0%
2. 50%
3. 100%
4. none of the above

2. 1 kWh is equivalent to

1. 86000 cal
2. 10000 Wh
3. 3.6 MJ
4. none of the above

3. A temperature of -40 deg F will be ____ deg C?

1. 0
2. -10
3. -40
4. none of the above

4. Unit of maximum demand is ____.

1. kVAh
2. kVA
3. kVAr
4. kWh

5. The pressure of 1 atm is equal to ____.

1. 10.1325 bar
2. 101.3 kpa
3. 1.033 mH2O
4. none of the above

6. For the purpose of calculating TOE for a designated consumer the calorific value of oil is taken as

1. 10500 kcal/kg
2. 10000 kcal/kg
3. 5000 kcal/kg
4. 8700 kcal/kg

7. 1 BTU is equal to

1. 252 Joule
2. 252 cal
3. 3600 kcal
4. 3.5 W

8. When the current leads the voltage in an AC electrical circuit, it is caused mainly due to

1. Inductive load
2. Resistive load
3. Capacitive load
4. none of the above

9. The power indicated in the name plate of a motor denotes ____.

1. minimum kW drawn by the motor
2. maximum kW drawn by the motor
3. maximum kVA drawn by the motor
4. none of the above

10. The law of conservation of energy is related with

1. third law of thermodynamics
2. second law of thermodynamics
3. first law of thermodynamics
4. none of the above

11. The producer gas is basically ____.

1. only CH4
2. only CO and CH4
3. CO, H2 and CH4
4. only CO and H2

12. The 'superheat' of steam is expressed as ____.

1. degrees centigrade above saturation temperature
2. degrees centigrade above critical temperature of the steam
3. degrees centigrade below the boiling point of water
4. all of the above

13. The electrical power unit GigaWatt (GW) may be expressed as

1. 1,000,000,000 MW
2. 1,000 MW
3. 1,000 kW
4. 10,000 W

14. Which of the following is not true of liquid fuels?

1. the viscosity of a liquid fuel is a measure of its internal resistance to flow
2. the viscosity of all liquid fuels decreases with increase in its temperature
3. higher the viscosity of liquid fuels, higher will be its heating value
4. viscous fuels need heat tracing

15. 300 litres of water in a tank is heated from 30 deg C to 70 deg C by using a direct steam with an enthalpy of 600 kcal/kg. The mass in kg of steam used is ____.

1. 10
2. 200
3. 40
4. none of the above

16. Which of the following is not a unit of energy?

1. Joule
2. Calorie
3. Watt
4. BTU

17. What is the heat content of the 200 litres of water at 50 deg C in terms of the basic unit of energy in kilo Joules (kJ)?

1. 3000
2. 4187
3. 1000
4. 41870

18. What is the 'TOE' of 125 Ton of coal which has GCV of 4000 kcal/kg

1. 40
2. 50
3. 400
4. 500

19. Power in a 3 phase AC system is

1. 3 x Voltage x Current
2. Voltage x Current
3. 1.73 x Voltage x Current
4. None of the above

20. To maximize the combustion efficiency, it is required to ____ in the flue gas?

1. maximize O2
2. maximize CO2
3. minimize CO2
4. maximize NOx

21. An electric heater of 230 V, 10 kW rating is installed for hot water generation in a hospital. The consumption per hour at 200 V is

1. 10 kWh
2. 8.7 kWh
3. 13.23 kWh
4. 7.56 kWh

22. The specific gravity of water is expressed as ____.

1. 1
2. 1 kg/m3
3. 1 g/cc
4. 1000 kg/m3

23. The number of moles in 90 kg of water is ____.

1. 5
2. 18
3. 2
4. none of the above

24. The type of energy possessed by the charged capacitor is

1. kinetic energy
2. electrostatic
3. potential
4. magnetic

25. The heat required to change a substance from liquid to vapor state without change of temperature is termed as

1. latent heat of fusion
2. latent heat of vaporization
3. heat capacity
4. sensible heat

26. The difference between GCV and NCV of coal is

1. the heat of vaporization of the moisture and atomic hydrogen (conversion to water vapor) in the fuel
2. the difference in heat released by using theoretical air and allowable excess air
3. difference in accounting the un-burnt content in the ash
4. none of the above

27. The calorific value of coal is 4,200 kCal/kg. Find out the oil equivalent of 1000 kg of coal if the calorific value of oil is 10,000 kCal/kg

1. 42,000 kg
2. 96 kg
3. 420 kg
4. 128 kg

28. Name plate kW rating of an induction motor indicates

1. input kW to the motor
2. output kW of the motor
3. minimum input kW to the motor
4. maximum input kW to the motor

29. Normally the maximum demand is charged for

1. kWh
2. kWAh
3. kVA
4. kVArh

30. For an electric heater, voltage remaining constant, the heat output ___ when resistance decreases.

1. decreases
2. increases
3. first increases then decreases
4. remains same

31. The active power consumption of AC 3-phase motive drive is determined by using which one of the following relations.

1. sqrt3 x V x I
2. sqrt3 x V^2 x I x Cosφ
3. 3 x V x I x Cosφ
4. sqrt3 x V x I x Cosφ

32. The law of conservation of energy states that energy

1. can be created and destroyed
2. is destroyed in the process of burning
3. cannot be converted from one form to another
4. is neither destroyed nor created

33. Latent heat is best described as the amount of heat required to cause a change in

1. both temperature and state
2. specific heat
3. state without a change in temperature
4. temperature without a change in state

34. Absolute pressure is

1. Gauge pressure
2. Gauge pressure + Atmospheric pressure
3. Atmospheric pressure
4. Gauge pressure - Atmospheric pressure

35. When heat flows from one place to another by means of liquid or gas, it is being transferred by

1. radiation
2. conduction
3. sublimation
4. convection

36. How many Watts are equivalent to one HP?

1. 760
2. 725
3. 740
4. 746

37. A process requires 100 kg of fuel with a calorific value of 5000 kCal/kg. If the system efficiency is 80%, then the losses would be

1. 100000 kCal
2. 400000 kCal
3. 50000 kCal
4. 20000 kCal

38. The lagging reactive power is required for

1. inductive load
2. resistive load
3. capacitive load
4. all of the above

39. To maximize the combustion efficiency, which of the following in the flue gas needs to be done?

1. maximize O2
2. maximize CO2
3. minimize CO2
4. maximize CO

40. Propane is an example of

1. nuclear energy
2. radiant energy
3. chemical energy
4. thermal energy

41. The density of a fuel oil is 0.86. Its specific gravity will be

1. 0.75
2. 0.86
3. 1.75
4. 0.0086

42. An indication of sensible heat content in air-water vapour mixture is

1. wet bulb temperature
2. dew point temperature
3. density of air
4. dry bulb temperature

43. The total mechanical energy of a body free falling in a vacuum

1. increases
2. decreases
3. remains the same
4. depends on the shape of the body

44. Which of the following is false?

1. electricity is high-grade energy
2. high grade forms of energy are highly ordered and compact
3. low grade energy is better used for applications like melting of metals rather than heating water for bath
4. the molecules of low grade energy are more randomly distributed than the molecules of carbon in coal

45. What will be the energy saving if one 1500 W, 25 litre water heater, normally on for 20 minutes/day for 250 days/year, is replaced with a 100 litre solar water heater?

1. 581 units
2. 750 units
3. 125 units
4. 169 units

46. Which of the following is not applicable to liquid fuels?

1. the viscosity of a liquid fuel is a measure of its internal resistance to flow.
2. the viscosity of all liquid fuels decreases with increase in its temperature
3. higher the viscosity of liquid fuels, higher will be its heating value
4. viscous fuels need heat tracing

47. Which of the following will be true of load factor for a continuous process

1. higher than batch process plants
2. comparable to that of a five star hotel with 60% occupancy
3. less than that of an energy efficient municipal lighting system
4. closer to the regional grid load factor

48. In a heat treatment furnace the material is heated up to 800 deg C from ambient 30 deg C. With specific heat 0.13 kCal/kg deg C, what is the energy content in one kg of material after heating?

1. 700 kCal
2. 250 kCal
3. 350 kCal
4. 100 kCal

49. Condensation of saturated steam releases

1. sensible heat
2. super heat
3. latent heat
4. none of the above

50. Calorific Value of coal is measured by a device called

1. bomb calorimeter
2. calorifier
3. infrared thermometer
4. none of these

51. The calorific value of coal is 5000 kCal/kg. Find out the oil equivalent of 200 kg of coal if the calorific value of oil is 10000 kCal/kg.

1. 100 kg
2. 108 kg
3. 105 kg
4. none of the above

52. Calculate the amount of electricity required to heat 100 litres of hot water from 20 to 60 deg C

1. 4.65 kWh
2. 0.465 kWh
3. 465 kWh
4. 2 kWh

53. One thousand litres of fuel oil cost Rs 20,000. How much does one kg of fuel oil cost if density is 0.98

1. 20.40
2. 20.0
3. 19.02
4. none of the above

54. Energy in one Tonne of Oil Equivalent (toe) corresponds to

1. 4.187 GJ
2. 1.162 MWh
3. 10,000 kcal
4. none of the above

55. If 1 kWh of electrical energy is used to heat 10 kg of ice at 0o C, what will be the temperature of water after melting? (Latent heat of fusion of ice is 80 kcal/kg)

1. 0°C
2. 6°C
3. 86°C
4. none of the above

56. The rate of energy transfer from a higher temperature to a lower temperature is measured in

1. kcal
2. Watt
3. Watts per second
4. none of the above.

57. The theoretical amount of electricity required to heat 500 litres of brine solution with a specific gravity of 1.2 and specific heat of 1 kcal/kg K from 30°C to 70 °C through resistance heating is_________

1. 27.9 kWh
2. 23.3 kWh
3. 20 kWh
4. none of the above

58. SI unit for energy is_____________

1. Watt
2. Kilogram
3. Newton
4. Joule

59. Which of the following has the lowest energy content in terms of MJ/kg?

1. LPG
2. Diesel
3. Bagasse
4. Furnace Oil

60. Which of the following industries has the highest Specific Electrical Energy Consumption?

1. Aluminum
2. Sugar
3. Paper & Pulp
4. Cement

61. Which of the following statements are true? Rice husk is a source of secondary energy ii) nuclear energy is non-renewable energy iii) electricity is basically a convenient form of primary energy iv) steam is a convenient form of secondary energy

1. (ii) & (iii)
2. (i) & (iii)
3. (ii) & (iv)
4. (ii) & (i)

62. An induction motor with 11 kW rating and a rated power factor of 0.9 in its name plate means

1. it will draw 12.22 kW at full load
2. it will draw 11 kW at full load
3. it will draw 9.9 kW at full load
4. it will deliver 11 kW at full load

63. The sector consuming major share of energy in India

1. Agriculture Sector
2. Transport Sector
3. Industrial Sector
4. Domestic Sector

64. The kW or HP of a motor given on the name plate indicates

1. The shaft output of the motor at part load
2. The shaft output of the motor at full load
3. The input power to the motor at the best efficiency point
4. The input power to the motor at any load

65. Which of the following has the highest Specific Heat?

1. Steel
2. Aluminium
3. Copper
4. Water

66. Heat transfer in an air cooled condenser occurs predominantly by

1. conduction
2. convection
3. radiation
4. none of the above

67. To arrive at the relative humidity at a point we need to know ___________ of air

1. DBT
2. WBT
3. Dew point
4. Both A and B

68. What is the heat content of 200 litres of water at 50 °C in terms of the basic unit of energy in kilo Joules (kJ)?

1. 30000
2. 23880
3. 10000
4. none of the above (BEE awarded 1 mark to every candidate attempting this question)

69. Which of the following is used for non-contact measurement of temperature

1. Thermocouples
2. Infrared Thermometer
3. Leaf type contact probe
4. All of the above

70. The lowest theoretical temperature to which water can be cooled in a cooling tower is

1. Difference between DBT and WBT of the atmospheric air
2. Average DBT and WBT of the atmospheric air
3. DBT of the atmospheric air
4. WBT of the atmospheric air

71. From Voltage, Amps and Power factor given in the name plate of a motor, one can calculate ________.

1. Rated output power
2. Shaft power
3. Rated input power
4. Both (b) & (c)

72. Which of the following comes under Capital cost in a project?

1. Design cost
2. Installation cost
3. Commissioning cost
4. All of the above

73. A three phase induction motor is drawing 10 Ampere at 440 Volts. If the operating power factor of the motor is 0.9 and the efficiency of the motor is 95%, then the mechanical shaft power of the motor is

1. 3.76 KW
2. 4.18 KW
3. 6.51 KW
4. 7.21 KW

74. The amount of CO2 produced in complete combustion of 18 Kg of Carbon is ______.

1. 50
2. 44
3. 66
4. 792

75. Which mode of heat transfer does not require medium?

1. Natural convection
2. Forced convection
3. Radiation
4. Conduction

76. The heat rate of a power plant is expressed as

1. kWh/kg of steam
2. kCal/kWh
3. kg of steam / kg of fuel
4. kWh / kVA

77. One Silicon cell in a PV module typically produces

1. 0.5 V
2. 1 V
3. 2 V
4. 12 V

78. To reduce the distribution losses within a plant, the capacitors should be located

1. Closest to the load
2. Farthest from the load
3. In the substation
4. Before the billing meter

79. Absolute pressure is measured as

1. Gauge pressure – Atmospheric pressure
2. Gauge pressure + Atmospheric pressure
3. Gauge pressure / Atmospheric pressure
4. none of the above

80. The dryness (x) fraction of superheated steam is taken as

1. x= 0
2. x= 0.9
3. x= 0.87
4. x= 1

81. When the evaporation of water from a wet substance is zero, the relative humidity of the air is likely to be

1. 0%
2. 100%
3. 50%
4. unpredictable

82. Which of the following statements are true? i) reactive current is necessary to build up the flux for the magnetic field of inductive devices ii) some portion of reactive current is converted into work iii) the cosine of angle between kVA and kVAr vector is called power factor iv) the cosine of angle between kW and kVA vector is called power factor

1. i & iv
2. ii & iii
3. i & iii
4. iii & iv

83. The electrical power unit Giga Watt (GW) may be written as

1. 1,000,000 MW
2. 1,000 MW
3. 1,000 kW
4. 1,000,000 W

84. The term missing in the following equation (kVA)² = (kVA cosφ)² + ( ? )² is

1. cosφ
2. sinφ
3. kVA sinφ
4. kVArh

85. 2000 kJ of heat is supplied to 500 kg of ice at 0°C. If the latent heat of fusion of ice is 335 kJ/kg then the amount of ice in kg melted will be

1. 1.49
2. 83.75
3. 5.97
4. None of the above

86. An electric heater draws 5 kW of power for continuous hot water generation in an industry. How much quantity of water in litres per min can be heated from 30°C to 85°C ignoring losses?.

1. 1.3
2. 78.18
3. 275
4. none of the above

87. An electric heater consumes 1000 Joules of energy in 5 seconds. Its power rating is:

1. 200 W
2. 1000 W
3. 5000W
4. none of the above

88. The quantity of heat required to raise the temperature of a given substance by 1 °C is known as:

1. sensible heat
2. specific heat
3. heat capacity
4. latent heat

89. Which of the following parameters is not considered for external Bench Marking?

1. scale of operation
2. energy pricing
3. raw materials and product quality
4. vintage of technology

90. The number of moles of water contained in 36 kg of water is ------------

1. 2
2. 3
3. 4
4. 5

91. A process electric heater is taking an hour to reach the desired temperature while operating at 440 V. It will take ------- hours to reach the same temperature if the supply voltage is reduced to 220 V.

1. 2
2. 3
3. 4
4. 5

92. The component of electric power which yields useful mechanical power output is known as

1. apparent power
2. active power
3. reactive power
4. none of the above

93. An oil fired boiler is retrofitted to fire coconut shell chips. Boiler thermal efficiency drops from 82% to 70%. What will be the percentage change in energy consumption to generate the same output

1. 12% increase
2. 14.6% increase
3. 17.1% decrease
4. 17.1% increase

94. A three phase induction motor is drawing 16 Ampere at 440 Volts. If the operating power factor of the motor is 0.90 and the motor efficiency is 92%, then the mechanical shaft power output of the motor is

1. 12.04 kW
2. 10.09 kW
3. 10.97 kW
4. None of the above

95. If a 2 KW immersion heater is used to heat 30litres of water at 30°C, what would be the temperature of water after 15 minutes? Assume no losses in the system

1. 87.3 °C
2. 44.3°C
3. 71.3 °C
4. none of the above

96. Red wood seconds is a measure of

1. Density
2. Viscosity
3. Specific gravity
4. Flash point

97. If Heat Rate of Power plant is 3000 kCal/kWh then efficiency of Power plant will be

1. 28.67%
2. 35%
3. 41%
4. None of the above

98. For every 10°C rise in temperature, the rate of chemical reaction doubles. When the temperature is increased from 30°C to 70°C, the rate of reaction increases __________ times.

1. 8
2. 64
3. 16
4. none of the above

99. If the reactive power drawn by a particular load is zero it means the load is operating at

1. Lagging power factor
2. Unity power factor
3. Leading power factor
4. none of the above

100. Capital cost are associated with

1. Design of Project
2. Installation and Commissioning of Project
3. Operation and Maintenance cost of project
4. both a and b

101. The kilowatt-hour is a unit of

1. power
2. work
3. time
4. force.

102. Which among the following is a green house gas?

1. Sulphur Dioxide
2. Carbon Monoxide
3. NO2
4. Methane

103. The quantity of heat required to raise the temperature of a given substance by 1 o C is known as:

1. sensible heat
2. specific heat
3. heat capacity
4. latent heat

104. The Metric Tonne of Oil Equivalent (MTOE) value of 125 tonnes of coal having GCV of 4000 kcal/kg is

1. 40
2. 50
3. 100
4. 125

105. In a coal fired boiler, hourly consumption of coal is 1300 kg. The ash content in the coal is 6%. Calculate the quantity of ash formed per day. Boiler operates 24 hrs/day.

1. 216 kg
2. 300 kg
3. 1872 kg
4. none of the above

106. A comparison of the trapping of heat by CO2 and CH4 is that

1. CH4 traps 21 times more heat in the atmosphere than does CO2
2. CO2 traps 21 times more heat in the atmosphere than does CH4
3. the same amount of heat is trapped by both CO2 and CH4
4. none of the above

107. In a chemical process two reactants A (300 kg) and B (400 kg) are used. If conversion is 50% and A and B react in equal proportions, the mass of the product formed is.

1. 300 kg
2. 350 kg
3. 400 kg
4. none of the above

108. Among which of the following fuel is the difference between the GCV and NCV maximum?

1. coal
2. furnace oil
3. natural gas
4. rice husk

109. The type of energy possessed by a charged capacitor is

1. kinetic energy
2. electrostatic
3. potential
4. magnetic

110. What is the heat content of 200 liters of water at 5°C in terms of the basic unit of energy in kilojoules ?

1. 3000
2. 2388
3. 1000
4. 4187

111. Nameplate kW rating of a motor indicates

1. input to the motor
2. rated output of the motor
3. no-load input to the motor
4. rated input to the motor

112. In inductive and resistive combination circuit, the resultant power factor under AC supply will be

1. less than unity
2. more than unity
3. zero
4. unity

113. How much carbon dioxide emission will be reduced annually by replacing 60 Watt incandescent lamp with a 15 Watt CFL Lamp, if emission per unit is 1 kg CO2 per kWh and annual burning is 3000 hours?

1. 45 ton
2. 3 ton
3. 0.135 ton
4. 183 ton

114. The annual electricity bill for a plant is Rs 110 lakhs and accounts for 38% of the total energy bill. Furthermore the total energy bill increases by 5% each year. The plant’s annual energy bill at the end of the third year will be about ________

1. Rs 335 lakhs
2. Rs 268 lakhs
3. Rs 386 lakhs
4. Rs 418 lakhs

115. A sum of Rs 100,000 is deposited in a bank at the beginning of a year. The bank pays 10% interest annually. How much money will be in the bank account at the end of the fifth year, if no money is withdrawn?

1. 161050
2. 150000
3. 155000
4. 160000

116. Portable combustion analyzers may have in-built chemical cells for measurement of stack gas components. Which combination of chemical cells for measurement of stack gas components is not possible?

1. CO, SOx, O2
2. CO2, O2
3. O2, NOx, SOx, CO
4. O2, CO

117. The weight (kg) of the water vapour in each kg of dry air(kg/kg) is termed as :

1. Specific Humidity
2. relative humidity
3. humidity
4. saturation ratio

118. The primary energy content of fuels is generally expressed in terms of ton of oil equivalent (toe) and is based on the following conversion factor

1. 1 toe=10x106 kCal
2. 1 toe=11630 kWh
3. 1 toe=41870 MJ
4. all the above

119. From rated V, A and PF given in the name-plate of a motor , one can calculate:

1. rated input Power
2. rated output Power
3. both a & b
4. none of these

120. A process requires 10 kg of fuel with a calorific value of 5000 kCal/kg. The system efficiency is 80% The losses then will be

1. 10000 kCal
2. 45000 kCal
3. 40000 kCal
4. 20000 kCal

121. Ratio of average load (kW) to maximum load (kW) is termed as

1. load factor
2. demand factor
3. form factor
4. utilization factor

122. The average gross efficiency of thermal power generation on all India bases is about

1. 30 – 34%
2. 36 – 38%
3. 39 - 41%
4. 25 - 28%

123. Assuming total conversion of electrical energy to heat energy, how much heat is produced by a 200 W heater in 5 minutes?

1. 200 kJ
2. 40 kJ
3. 1000 kJ
4. 60 kJ

124. A motor with 10 kW rating in its name plate, will draw Input power of____

1. 10 kW at full load
2. more than 10 kW at full load
3. less than 10 kW at full load
4. 10 kW at 110% of full load

125. Which of the following statements is not true regarding Maximum Demand Control?

1. Maximum demand control offers a way of ‘shaving’ the peaks and ‘filling’ the valleys in the consumer load diagram
2. Maximum demand control is carried out by concerned utility at customer premises
3. Maximum demand control focuses on critical load for management
4. All of the above

126. Which of the following statements is false?

1. reactive current is necessary to build up the flux for the magnetic field of inductive devices
2. some portion of reactive current is converted into useful work
3. Cosine of the angle between kVA and kW vector is called power factor
4. power factor is unity in a pure resistive circuit

127. Steam leak reduction program can be best achieved through

1. Small Group Activities
2. Autonomous Maintenance
3. TPM
4. All of the above

128. Consider two competitive projects A and B each entailing investment of Rs.85,000/- . Project A returns Rs.50,000 at the end of each year, but Project B returns Rs.115,000 at the end of Year 2. Which project is superior?

1. project A since it starts earning by end of first year itself and recovers cost before end of two years
2. project B since it offers higher return before end of two years
3. both projects are equal in rank
4. insufficient information to assess the superiority

129. In a contract when all or part of the savings are guaranteed by contractor, and all or part of the costs of equipment and/or services are paid out of savings as they are achieved, is termed as

1. traditional contract
2. guaranteed saving performance contract
3. shared saving performance contract
4. extended technical guarantee contract

130. If 3350 kJ of heat is supplied to 20 kg of ice at 0o C, how many kg of ice will melt into water at 0o C (latent heat of melting of ice is 335 kJ/kg)

1. 1 kg
2. 4.18 kg
3. 10 kg
4. 29 kg

131. If oxygen rich combustion air (25% vol oxygen) is supplied to a furnace instead of normal air (21% vol oxygen), the % CO2 in flue gases will

1. reduce
2. increase
3. remain same
4. will become zero

132. An example of stored mechanical energy is

1. water in a reservoir
2. an arrow in a stretched bow
3. an air-borne aeroplane
4. you on top of a mountain

133. Mega Volt Ampere (MVA) in a three phase electrical circuit could be written as

1. (Voltage x Ampere) / 1,000
2. (Voltage x Ampere) / 1,000,000
3. Voltage x Ampere x 1,000
4. none of the above

134. When the current lags the voltage in an alternating current system, it is caused mainly due to

1. resistive load
2. capacitive load
3. inductive load
4. none of the above

135. Which energy source is indirect in an overall energy balance in the generation of electricity by a photovoltaic cell?

1. commercial energy
2. wave energy
3. sun light
4. none of the above

136. What is the 'toe' of 125 Ton of coal which has GCV of 4000 kcal/kg

1. 40
2. 50
3. 400
4. 500

137. The quantity of heat required to raise the temperature of a substance by 1 degree C is known as

1. sensible heat
2. specific heat
3. heat capacity
4. latent heat

138. Active power in an alternating current (AC) circuit is given by

1. kVA x power factor
2. (kVA^2 - kVAr^2)^1/2
3. [(kVA + kVAr) x (kVA - kVAr)]^1/2
4. all of the above

139. Nameplate kW or HP rating of a motor indicates

1. input kW to the motor
2. output kW of the motor
3. minimum input kW to the motor
4. maximum input kW to the motor

140. A 230V, 100 W rated Incandescent bulb is operated at a constant voltage of 200V. The power consumption of the bulb is ____.

1. 80W
2. 76W
3. 87W
4. 100W

141. The input current drawn by 3-ph 10 kW induction motor is 20 Amps at 0.8 pf. The input voltage is 410V. The motor efficiency is ____.

1. 86%
2. 90%
3. 88%
4. None of the above

142. If 3500 kJ of heat is supplied to 22 kgs of ice at 0 degC, how many kg of ice will melt into water at 0 degC (latent heat of melting is 330 kJ/kg).

1. 10.606 Kg
2. 12 Kg
3. 22 Kg
4. 15 Kg

143. Which among the following fuels has the highest calorific value?

1. Coal
2. Diesel
3. Hydrogen
4. Natural Gas

144. The vacuum recorded in a steam power plant is 720 mmHg and the atmospheric pressure is 760 mmHg. The absolute pressure in kg/cm^2 is ____.

1. 0.526
2. 0.053
3. 5.26
4. None of the above

145. The amount of electricity in kWh used to heat 150 liters of water from 20 degC to 60 degC through resistance heating is ____.

1. 0.698 kWh
2. 698 kWh
3. 6.98 kWh
4. 69.8 kWh

146. The efficiency (%) for a thermodynamic process with E(input) = 100 units and Loss = 55 units will be ____.

1. 10%
2. 45%
3. 55%
4. Data Insufficient

147. The dryness (x) fraction of dry saturated steam is ____.

1. x = 0.87
2. x = 0.9
3. x = 1
4. x = 0

148. Ten units of electricity are equivalent to ____.

1. 10 ToE
2. 10 kCal
3. 10 KJ
4. 8600 kCal

149. Select the incorrect statement related to energy basics ____.

1. Superheating is a process of heating vapor above evaporation temperature.
2. Pump is used to move the fluid in process of natural convection.
3. Calorific value is a measure of energy content of organic matter of fuel.
4. Internal resistance of a fluid is measured as viscosity of a fluid.

150. Why radiation heat transfer is prominent in applications like boiler and furnace?

1. It does not require medium
2. Heat transfer is proportional to T^4
3. It uses electromagnetic waves to transfer heat
4. All of above

151. Temperature of steam will be highest in following condition at same pressure ____.

1. Wet steam
2. Saturated steam
3. Superheated steam
4. At all stages temperature is same

152. The Specific heat is high for ____.

1. Lead
2. Water
3. Mercury
4. Alcohol

153. The name plate kW or HP of a motor indicates ____.

1. Input power drawn
2. Output power
3. Max input power
4. Minimum input power

154. 2000 kJ of heat is supplied to 500 kg of ice at 0 degC. If the latent heat of fusion of ice is 335 kJ/kg then the amount of ice in kg melted will be ____.

1. 1.49
2. 83.75
3. 5.97
4. None of the above

155. The number of moles of water contained in 27 kg of water is ____.

1. 5
2. 3
3. 4
4. 1.5

156. The amount of energy transfer from a higher temperature to a lower temperature is measured in ____.

1. kcal
2. Watt
3. Watts per second
4. none of the above

157. The amount of electricity required to heat 200 litres of water from 30 degC to 70 degC through resistance heating is ____.

1. 0.93 kWh
2. 9.3 kWh
3. 930 kWh
4. 8 kWh

158. A process requires 100 kg of fuel with a calorific value of 5000 kcal/kg for heating with a system efficiency of 83%. The loss in kcal would be ____.

1. 235,000 kCal
2. 85,000 kCal
3. 103680 kCal
4. 415,000 kCal

159. Propane is an example of stored ____ energy.

1. Nuclear
2. Radiant
3. Chemical
4. Mechanical

160. In a heat treatment furnace the material is heated up to 1053 K from ambient temperature of 303 K. Considering the specific heat of material as 0.125 kCal/kg degC, what is the energy content gained by one kg of material after heating?

1. 94 kCal
2. 250 kCal
3. 350 kCal
4. 100 kCal

161. The quantity of heat required to convert one kg of a liquid into vapour without change of temperature is called ____.

1. latent heat of fusion
2. specific heat
3. sensible heat
4. Latent heat of Evaporation

162. The energy consumed by a 55 kW motor loaded at 40 kW over a period of 4 hours is:

1. 220 kW
2. 220 kWh
3. 160 kWh
4. 160 kW

163. 3.6 units of electricity is equivalent to ____ of kCal of heat units:

1. 680
2. 860
3. 3096
4. 3600

164. Which of the following most closely represents the heat content of 1 kg of LPG:

1. 8000 kilo Calorie
2. 12500 kilo Joule
3. 12500 kilo Calorie
4. 8000 kilo Joule

165. Resistance of 250 V incandescent lamp drawing 0.5 A:

1. 5,000 Ω
2. 500 Ω
3. 50 Ω
4. 5 Ω

166. A boiler receives 100 MJ of fuel energy. The steam output is 70 MJ, the flue gas loss is 20 MJ and the radiation plus unaccounted loss is 10 MJ. What is the boiler efficiency?

1. 65%
2. 60%
3. 70%
4. 75%

167. 1 tonne of oil equivalent =:

1. 41,868 MJ
2. 1,000 kcal
3. 1,000 kWh
4. 1,000 BTU

168. Maximum specific heat among the following:

1. Water
2. Lead
3. Mercury
4. Iron

169. Heat required for Cooling 2000 kg of water for ΔT of 10°C ____________

1. 2,000 kcal
2. 20,000 kcal
3. 200 kcal
4. 2×10^5 kcal

170. The relation between gauge pressure (pg), system pressure (ps), and atmospheric pressure (pa) is:

1. pg = ps + pa
2. pg = ps − pa
3. ps = pg − pa
4. pa = ps + pg

171. 'Daylight harvesting' in lighting systems means:

1. Collecting solar energy for night lighting
2. Using flat plate collectors for heating
3. Adjusting artificial lighting based on natural daylight
4. Storing energy in battery banks

172. Power rating of an electrical heater consuming 12,000 J/min is:

1. 12 W
2. 100 W
3. 200 W
4. 12,000 W

173. Calculate the energy consumed by a 200-watt appliance used for 5 hours a day over 30 days.

1. 30 kWh
2. 27000 kCal
3. 6500 kJ
4. 30 kJ/h

174. Which of the following is not true, equivalent to 1 atm pressure?

1. 1 atm = 101.3 kPa
2. 1 atm = 10332 mmWC
3. 1 atm = 14.7 psi
4. 1 atm = 0.98 kg/cm2

175. Redwood Seconds is measure of ____________

1. Density
2. Viscosity
3. Specific Gravity
4. Flash Point

176. What is the heat content of 500 liters of water at 6°C in terms of the basic unit of energy in kilojoules?

1. 12000
2. 3000
3. 500
4. None of the above

177. Heat transfer in an air-cooled condenser occur predominately by

1. Conduction
2. Convection
3. Radiation
4. All of the above

178. When the evaporation of water from wet substance is zero, the relative humidity of air is likely to be

1. 0%
2. 50%
3. 100%
4. Unpredictable

179. If we heat air without changing absolute humidity, % relative humidity will

1. Increase
2. Decrease
3. No change
4. Can't Say

180. Among which of the following fuel the difference between the GCV and NCV is maximum

1. Coal
2. Furnace Oil
3. Natural Gas
4. Rice Husk

181. An induction motor with 30 kW rating and efficiency of 85% in its name plate means

1. It will draw 35.29 kW at full load
2. it will always draw 30 kW at full load
3. it will draw 25.5 kW at full load
4. it will draw 28.23 kW at full load

182. Energy content in 2500 kgs of coal with a calorific value of 4000 kcal/kg in terms of toe would be

1. 1 toe
2. 10 toe
3. 100 toe
4. 1000 toe

183. An electric iron of power 2000 watts is used for a total of 120 minutes per month. Compute its monthly electricity consumption

1. 2.0 kWh
2. 2.4 kWh
3. 4.0 kWh
4. 24.0 kWh

184. The dryness fraction (x) of superheated steam will be

1. x = 0.8
2. x = 0.9
3. x = 1
4. x = 0

185. The specific heat of water is approximately:

1. 470 J/kg°C
2. 910 J/kg°C
3. 2400 J/kg°C
4. 4200 J/kg°C

186. One kilowatt-hour (1 kWh) equals:

1. 860 kcal = 3.6 MJ
2. 252 kcal = 1.055 MJ
3. 1000 kcal = 4.2 MJ
4. 11,630 kcal = 41.8 MJ

187. The power drawn by a resistive heater varies with applied voltage as:

1. P ∝ V
2. P ∝ V^2
3. P ∝ 1/V
4. P ∝ √V

188. A 5 kW heater rated at 230 V is operated at 200 V. The approximate power it now draws is:

1. 5.0 kW
2. 4.35 kW
3. 3.78 kW
4. 2.50 kW

189. The active power in a balanced three-phase AC system is given by:

1. P = Vl × Il × cosθ
2. P = √3 × Vl × Il × cosθ
3. P = 3 × Vl × Il
4. P = Vl × Il ÷ √3

190. A 3-phase motor draws 25 A at 440 V with power factor 0.9 for 1 hour. The energy consumed is approximately:

1. 9.9 kWh
2. 12.5 kWh
3. 17.15 kWh
4. 19.8 kWh

191. Power factor (PF) of an AC load is equal to:

1. kVAR / kVA
2. kW / kVA
3. kVA / kW
4. kW / kVAR

192. The latent heat of vaporization of water at 100°C is approximately:

1. 335 kJ/kg
2. 419 kJ/kg
3. 2257 kJ/kg
4. 4200 kJ/kg

193. Which fuel has the LARGEST difference between its gross (GCV) and net (NCV) calorific value?

1. Coal
2. Furnace oil
3. Natural gas
4. Bagasse

194. In a steam table, a dryness fraction (x) equal to 1 represents:

1. Saturated water
2. Wet steam
3. Dry saturated steam
4. Superheated steam

195. Which mode of heat transfer requires NO material medium for the transport of heat?

1. Conduction
2. Convection
3. Radiation
4. Forced convection

196. One standard atmosphere (1 atm) is equal to:

1. 1.01325 bar = 760 mmHg
2. 0.5 bar = 380 mmHg
3. 2.0 bar = 1520 mmHg
4. 10 bar = 7600 mmHg

197. The rate of energy transfer from a higher temperature to a lower temperature is measured in

1. kcal
2. Watt
3. Watts per Second
4. none of the above

198. What is the heat content of 200 liters of water at 5 oC in terms of the basic unit of energy in kilojoules?

1. 3000
2. 2388
3. 1000
4. 4187

199. Which of the following has the highest specific heat?

1. lead
2. mercury
3. water
4. alcohol

200. Which of the following is false?

1. 1 calorie = 4.187 kJ
2. 1 calorie = 4.187J
3. 1000 kWh = 1 MWh
4. 860 kcal = 1 kWh

201. The term missing in the following equation (kVA)² = (kVA cos phi)² + ( ? )² is

1. cos phi
2. sin phi
3. kVA sin phi
4. kVArh

202. The weight (kg) of the water vapour in each kg of dry air (kg/kg) is termed as:

1. Specific Humidity
2. relative humidity
3. humidity
4. saturation ratio

203. 2000 kJ of heat is supplied to 500 kg of ice at 0 oC. If the latent heat of fusion of ice is 335 kJ/kg then the amount of ice in kg melted will be

1. 1.49
2. 83.75
3. 5.97
4. None of the above

204. An electric heater draws 5 kW of power for continuous hot water generation in an industry. How much quantity of water in litres per min can be heated from 30 oC to 85 oC ignoring losses?

1. 1.3
2. 78.18
3. 275
4. none of the above

205. To improve the boiler efficiency, which of the following needs to be done

1. maximize O2 in flue gas
2. maximize CO2 in flue gas
3. minimize CO2 in flue gas
4. maximize CO in flue gas

206. The quantity of heat required to raise the temperature of 1 kg of water by 1 OC is termed as

1. latent heat
2. one kilojoule
3. one kilo calorie
4. none of the above

207. In a DG set, the generator is consuming 400 litres per hour diesel oil. If the specific fuel consumption of this DG set in 0.30 litres/kWh at that load then what is the kVA loading of the set at 0.6 power factor

1. 1200 KVA
2. 2222 KVA
3. 600 KVA
4. 1600 KVA

208. In a 50 Hz AC cycle, the current reverses directions ________ times per second

1. 50 times
2. 100 times
3. Two times
4. 25 times

209. If we heat the air without changing absolute humidity,% relative humidity will

1. increase
2. decrease
3. no Change
4. can't say

210. If the pressure of water is 0.7 kg/cm2 then boiling point will be approximately

1. 100
2. 73
3. 114
4. Can't say

211. If heat rate of power plant is 860 kcal/kWh then the cycle efficiency of power plant will be

1. 41%
2. 55%
3. 100%
4. 86%

212. For expressing the primary energy content of a fuel in tonnes of oil equivalent (toe) which of the following conversion factors is appropriate

1. toe=1x106 kcal
2. toe=116300 kwh
3. toe=41.870 GJ
4. all the above

213. At standard atmospheric pressure, specific enthalpy of saturated water, having temperature of 50 OC will be _________ kcal/kg

1. 1
2. 50
3. 100
4. Can't say

214. Among which of the following fuels, the difference between the GCV and NCV is maximum

1. coal
2. furnace Oil
3. natural gas
4. rice husk

215. A 400W lamp was switched on for 10 hours per day. The supply volt is 230V (current= 2 amps & PF= 0.8). What is the energy consumption per day

1. 3.68 kWh
2. 6.37 kWh
3. 0.37 kWh
4. 4.0 kWh

216. 100 tons of coal with a GCV of 4200 kcal/kg can be expressed in 'tonnes of oil equivalent' as

1. 42
2. 50
3. 420
4. 125

217. The term missing in the following equation (kVA) 2 = (kVA cos phi) 2 + (?)2 is

1. cos phi
2. sin phi
3. kVA sin phi
4. kVArh

218. 2000 kJ of heat is supplied to 500 kg of ice at 0oC. If the latent heat of fusion of ice is 335 kJ/kg then the amount of ice in kg melted will be

1. 1.49
2. 83.75
3. 5.97
4. None of the above

219. An electric heater draws 5 kW of power for continuous hot water generation in an industry. How much quantity of water in litres per min can be heated from 30oC to 85oC ignoring losses?.

1. 1.3
2. 78.18
3. 275
4. none of the above

220. The quantity of heat required to raise the temperature of a given substance by 1 oC is known as:

1. sensible heat
2. specific heat
3. heat capacity
4. latent heat

221. To arrive at the relative humidity at a point we need to know___________of air

1. dry bulb temperature
2. wet bulb temperature
3. enthalpy
4. both a & b

222. What is the heat content of the 200 liters of water at 500 °C in terms of the basic unit of energy in Kilo Joules

1. 30000
2. 23880
3. 10000
4. 41870

223. If 1 kWh of electrical energy is used to heat 10 kg of ice at 0 °C, what will be the temperature of water after melting? (Latent heat of fusion of ice is 80 kcal/kg)

1. 0 °C
2. 6 °C
3. 86 °C
4. none of the above

224. The theoretical amount of electricity required to heat 500 litres of brine solution with a specific gravity of 1.2 and specific heat of 1 kcal/kg K from 30 °C to 70 °C through resistance heating is

1. 27.9 kWh
2. 23.3 kWh
3. 20 kWh
4. none of the above

225. SI unit for energy is

1. Watt
2. Kilogram
3. Newton
4. Joule

226. Which of the following has the lowest energy content in terms of MJ/kg?

1. LPG
2. Diesel
3. Furnace Oil
4. Coal

227. Steam contains 10% moisture by mass, its dryness fraction x is _________.

1. 0.1
2. 1
3. 0.9
4. None of the above

228. Which of the following will have maximum value when expressed as MTOE (Metric Tonne of Oil Equivalent)?

1. 1000 tonnes of furnace oil
2. 10,000 kWh of electrical energy
3. 1000 tonnes of bituminous coal
4. 1000 tonnes of lignite

229. Which of the following is not true of natural gas?

1. Requires more excess air compared to oil
2. Consists mainly of methane
3. Becomes liquefied when cooled to -161 °C
4. All of the above

230. If wet bulb and dry bulb temperatures read the same, the relative humidity is

1. 0%
2. 50%
3. 100%
4. none of the above

231. Unit of maximum demand is

1. kVAh
2. kVA
3. kVAr
4. kWh

232. The pressure of 1 atm is equal to

1. 10.1325 bar
2. 101.3 kPa
3. 1.033 mH2O
4. none of the above

233. 1 BTU is equal to

1. 252 Joule
2. 252 cal
3. 3600 kcal
4. 3.5W

234. The power indicated in the name plate of a motor denotes

1. minimum kW drawn by the motor
2. maximum kW drawn by the motor
3. maximum kVA drawn by the motor
4. none of the above

235. The 'superheat' of steam is expressed as

1. degrees centigrade above saturation temperature
2. degrees centigrade above critical temperature of the steam
3. degrees centigrade below the boiling point of water
4. all of the above

236. 300 liters of water in a tank is heated from 30 deg C to 70 deg C by using a direct steam with an enthalpy of 600 kcal/kg. The mass in kg of steam used is

1. 10
2. 200
3. 40
4. none of the above

237. What is the heat content of the 200 liters of water at 50 deg C in terms of the basic unit of energy in kilo Joules (kJ)

1. 3000
2. 4187
3. 1000
4. 41870

238. The specific gravity of water is expressed as

1. 1
2. 1 kg/m3
3. 1 g/cc
4. 1000 kg/m3

239. The amount of energy transfer from a higher temperature to a lower temperature is measured in

1. kcal
2. Watt
3. Watts per second
4. none of the above

240. The amount of electricity required to heat 200 litres of water from 30 deg C to 70 deg C through resistance heating is

1. 0.93 kWh
2. 9.3 kWh
3. 930 kWh
4. 8 kWh

241. Propane is an example of ____ stored energy

1. Nuclear
2. Radiant
3. Chemical
4. Mechanical

242. In a heat treatment furnace the material is heated up to 1053 K from ambient temperature of 303 K. Considering the specific heat of material as 0.125 kcal/kg deg C, what is the energy content gained by one kg of material after heating?

1. 94 kcal
2. 250 kcal
3. 350 kcal
4. 100 kcal

243. The quantity of heat required to convert one kg of a liquid into vapour without change of temperature is called

1. latent heat of fusion
2. specific heat
3. sensible heat
4. Latent heat of Evaporation

244. 3.6 units of electricity is equivalent to ____ kcal of heat units:

1. 680
2. 860
3. 3096
4. 3600

245. Which of the following most closely represents the heat content of 1 kg of LPG:

1. 8000 kcal
2. 12500 kcal
3. 12500 kJ
4. 8000 kJ

246. 2000 kJ of heat is supplied to 500 kg of ice at 0 deg C. If the latent heat of fusion of ice is 335 kJ/kg then the amount of ice in kg melted will be

1. 1.49
2. 83.75
3. 5.97
4. None of the above

247. A 230V, 100 W rated Incandescent bulb is operated at a constant voltage of 200V. The power consumption of the bulb is

1. 80W
2. 76W
3. 87W
4. 100W

248. The input current drawn by 3-ph 10 kW induction motor is 20 Amps at 0.8 pf. The input voltage is 410V. The motor efficiency is

1. 86%
2. 90%
3. 88%
4. None of the above

249. If 3500 kJ of heat is supplied to 22 kgs of ice at 0 deg C, how many kg of ice will melt into water at 0 deg C (latent heat of melting is 330 kJ/kg)?

1. 10.606 Kg
2. 12 Kg
3. 22 Kg
4. 15 Kg

250. The vacuum recorded in a steam power plant is 720 mmHg and the atmospheric pressure is 760 mmHg. The absolute pressure in kg/cm2 is

1. 0.526
2. 0.053
3. 5.26
4. None of the above

251. The amount of electricity in kWh used to heat 150 liters of water from 20 deg C to 60 deg C through resistance heating is

1. 0.698 kWh
2. 698 kWh
3. 6.98 kWh
4. 69.8 kWh

252. The efficiency (%) for a thermodynamic process with E(input) = 100 units and Loss = 55 units will be

1. 10%
2. 45%
3. 55%
4. Data Insufficient

253. The dryness (x) fraction of dry saturated steam is

1. x = 0.87
2. x = 0.9
3. x = 1
4. x = 0

254. Ten units of electricity are equivalent to

1. 10 ToE
2. 10 kCal
3. 10 KJ
4. 8600 kCal

255. When the evaporation of water from a wet substance is zero, the relative humidity of air is likely to be

1. 0%
2. 10%
3. 50%
4. 100%

256. Select the incorrect statement related to energy basics

1. Superheating is a process of heating vapor above evaporation temperature.
2. Pump is used to move the fluid in process of natural convection.
3. Calorific value is a measure of energy content of organic matter of fuel.
4. Internal resistance of a fluid is measured as viscosity of a fluid.

257. Why is radiation heat transfer prominent in applications like boiler and furnace?

1. It does not require medium
2. Heat transfer is proportional to T^4
3. It uses electromagnetic waves to transfer heat
4. All of above

258. Temperature of steam will be highest in following condition at same pressure

1. Wet steam
2. Saturated steam
3. Superheated steam
4. At all stages temperature is same

259. The Specific heat is high for

1. Lead
2. Water
3. Mercury
4. Alcohol

260. The name plate kW or HP of a motor indicates

1. Input power drawn
2. Output power
3. Max input power
4. Minimum input power

261. What is the heat content of 500 liters of water at 6 deg C in terms of the basic unit of energy in kilojoules?

1. 12000
2. 3000
3. 500
4. None of the above

262. Heat transfer in an air-cooled condenser occurs predominately by

1. Conduction
2. Convection
3. Radiation
4. All of the above

263. Resistance of 250 V incandescent lamp drawing 0.5 A:

1. 5,000 ohm
2. 500 ohm
3. 50 ohm
4. 5 ohm

264. 1 tonne of oil equivalent =

1. 41,868 MJ
2. 1,000 kcal
3. 1,000 kWh
4. 1,000 BTU

265. Heat required for cooling 2000 kg of water for a delta T of 10 deg C ____________

1. 2,000 kcal
2. 20,000 kcal
3. 200 kcal
4. 2x10^5 kcal

266. The relation between gauge pressure (pg), system pressure (ps), and atmospheric pressure (pa) is:

1. pg = ps + pa
2. pg = ps - pa
3. ps = pg - pa
4. pa = ps + pg

1. List five forms of energy with examples.

2. Distinguish between potential energy and kinetic energy with examples and their defining equations.

3. Define work, energy and power and give their SI units and defining relations.

4. A portable machine requires a force of 200 N to move it. How much work is done if it is moved 20 m, and what average power is used if the movement takes 25 s?

5. Differentiate between Direct Current (DC) and Alternating Current (AC).

6. Define ampere, volt and frequency (with units) as used in electricity basics.

7. State Ohm's law definition of resistance and define conductance, with units.

8. Give the relation for electrical power and energy in a DC/AC circuit. An electric heater consumes 1.8 MJ when connected to a 250 V supply for 30 minutes. Find its power rating and the current drawn.

9. A 100 W electric light bulb is connected to a 250 V supply. Determine (a) the current flowing in the bulb, and (b) the resistance of the bulb.

10. An electric kettle has a resistance of 30 ohm. What current flows when connected to a 240 V supply, and what is its power rating?

11. An electric heater of 230 V, 5 kW rating is used for hot water generation. Find the electricity consumption per hour (a) at rated voltage and (b) at 200 V.

12. Explain the power triangle and define active power (kW), reactive power (kVAR), apparent power (kVA) and power factor.

13. Define power factor.

14. Give the expressions for power in single-phase and three-phase balanced AC loads, and state which loads use single-phase power.

15. A 400 W mercury vapour lamp is switched on for 10 hours per day at 230 V (current 2 A, PF 0.8). Find the energy consumption per day.

16. A 250 W sodium vapour street lamp runs at 230 V for 12 hours/day, drawing 2 A at power factor 0.85. Calculate the energy consumption per day.

17. How is a motor's horsepower rating converted to kVA, and what is the significance of the nameplate rating?

18. A 3-phase AC induction motor (20 kW) is used for pumping. Measured values: 440 V, 25 A, PF 0.90. Find the energy consumption in one hour.

19. A 3-phase 10 kW motor has nameplate 415 V, 18.2 A, 0.9 PF. Actual measurement shows 415 V, 12 A, 0.7 PF. Find the motor loading and actual input power.

20. A 10 kW rated motor has full-load efficiency 85%. Actual input measurement shows 415 V, 10 A, PF 0.68. Find the motor loading in percentage.

21. Define temperature and give the Celsius, Fahrenheit and Kelvin scales with their conversions.

22. Define pressure and explain absolute, gauge and atmospheric pressure with their relationship.

23. State the value of standard atmospheric pressure in the various units used for pressure measurement.

24. Define heat and the calorie/kilocalorie, and give the relationship between calorie and joule.

25. Define specific heat and give its units. Why are two specific heats defined for gases?

26. Give the specific heat values (J/kg.C) of common substances from the guidebook table.

27. Differentiate between sensible heat and latent heat, and give the formula for sensible heat.

28. Define fusion, vaporization and condensation, and the terms melting point and boiling point.

29. Define latent heat of fusion, give its value for ice, and the formula used.

30. Define latent heat of vaporization, state its value for water, and explain condensation in heat terms.

31. What is superheating of steam, why is it done, and what is the dryness fraction (x)?

32. Define humidity, specific humidity (humidity ratio) and relative humidity (RH).

33. Define dew point, dry-bulb temperature and wet-bulb temperature, and state their relationship at 100% RH.

34. What is enthalpy of air and how is it determined?

35. Define fuel density, specific gravity and viscosity, and state the units of viscosity.

36. How is the calorific value of a fuel measured, and what is the difference between GCV and NCV?

37. Name and explain the three primary modes of heat transfer.

38. Describe the stages of evaporation and define enthalpy and specific enthalpy of steam.

39. State the specific enthalpy of saturated water, saturated steam and evaporation for water at standard atmospheric pressure.

40. State the three laws of thermodynamics.

41. What is entropy, and what does the second law of thermodynamics tell us about heat-engine efficiency?

42. List the SI base units, and give the SI derived units (with symbols) relevant to energy management.

43. Give the key energy unit conversions for kWh, joule, BTU, kcal and HP.

44. Define 1 kg oil equivalent and 1 MTOE, and give the standard calorific values used for fuels in toe accounting.

45. Give the formulas used to convert solid, liquid and gaseous fuel consumption to MTOE.

46. What is the toe of 125 tonnes of coal having GCV 4000 kcal/kg?

47. Define chemical energy and nuclear energy with their characteristic equations.

48. Why does current lag voltage in an AC system, and how is the power factor improved?

49. A facility has connected load 500 kW and contract demand 500 kVA. Monthly maximum demand approx 350 kW at 0.85 PF. Demand charge is Rs 300 per kVA/month and minimum billing demand is 80% of contract demand. a) Determine the current demand in kVA. b) Calculate excess demand charges above minimum billing demand. c) Find the minimum power factor required to avoid excess demand charges.

50. A 10 HP induction motor (nameplate 415 V, 12 A, PF 0.9) is audited. Monitoring shows reactive power 2 kVAR and power factor 0.758. Calculate the percentage loading of the motor.

51. A drilling machine draws 5 kW input at 50% efficiency to drill a 5 kg aluminium block. A 45 C temperature rise is observed over 100 s (specific heat of aluminium = 900 J/kg.K). What percentage of the machine's output power is lost to the surroundings?

52. A single-phase electric geyser is rated 2000 W at 230 V. Calculate (a) rated current, (b) resistance in ohms, (c) actual power drawn when the measured supply voltage is 210 V.

53. A furnace shell (4 tonnes) is to be cooled from 95 C to 45 C. The maximum permissible rise in water temperature is 5 C. Compute the quantity of water required. (Cp shell = 0.122 kcal/kg.C, Cp water = 1 kcal/kg.C)

54. Explain the difference between contract demand and maximum demand.

55. An induction motor draws 8 kW with a lagging reactive power of 4 kVAR. Calculate the operating power factor.

56. The initial temperature of 150 g of ethanol was 22 C. What is the final temperature if 3240 J is supplied? (Specific heat of ethanol = 2.44 J/g.C)

57. When the same quantity of heat is added to equal masses of iron and copper, the iron's temperature rises by 15 C. Find the rise in copper's temperature. (Cp iron = 470 J/kg.C, Cp copper = 390 J/kg.C)

58. A textile plant's monthly use: 700,000 kWh electricity, 40 kL furnace oil (sp.gr 0.92, GCV 10,000 kcal/kg), 360 t coal (GCV 3450 kcal/kg), 10 kL HSD (sp.gr 0.885, GCV 10,500 kcal/kg). Compute the monthly energy use in MTOE. (1 kWh = 860 kcal, 1 kg oil equiv = 10,000 kcal)

59. Give the relationship between absolute and gauge pressure, and list four units used for pressure measurement.

60. A gas-fired water heater heats water flowing at 20 litre/min from 25 C to 85 C. If the GCV of gas is 9200 kcal/kg and heater efficiency 82%, find the gas combustion rate in kg/min.

61. In a textile unit, 25,000 kg/hr water is heated from 28 C to 80 C by steam. By recovering effluent heat, water is pre-heated to 45 C before steam raises it to 80 C. Estimate the steam saving (kg/hr), latent heat of steam = 520 kcal/kg.

62. A tank with 600 kg kerosene is heated from 10 C to 40 C in 20 minutes using 4 bar(g) steam (latent heat hfg = 2108.1 kJ/kg). Cp of kerosene = 2.0 kJ/kg.C. Heat losses negligible. Determine the steam flow rate in kg/hr.

63. Boiler feed water is at 70 C. Returning condensate is at 86 C and makeup water at 27 C. Determine the percentage of condensate water that can be recovered (mass/heat balance).

64. A paint drier needs 75.4 m3/min of air at 93 C heated by a steam coil. How many kg/hr of steam at 4 bar are needed? (air density 1.2 kg/m3, Cp air 0.24 kcal/kg.C, ambient 32 C, latent heat of steam 510 kcal/kg)

65. Calculate the heat energy required to raise 200 kg of water from 30 C to 80 C (Cp water = 1 kcal/kg.C). Express the answer in kcal and kWh.

66. A pump runs at constant head/flow delivering 250 litre/s at 100 m head, drawing 300 kW. Calculate the energy consumption to pump 13,500 kL of water.

67. A conveyor delivers coal 1 m wide with a 0.25 m bed height at 0.5 m/s. Determine the coal delivery in tons/hour (coal density 1.1 ton/m3).

68. A coal sample contains 60% carbon and 23% ash. The combustion refuse contains 7% carbon (rest ash). Compute the percentage of original carbon remaining unburnt in the refuse.

69. A DG set gives 3.5 kWh per litre of diesel. Cooling-water loss is 28% and exhaust loss 32% of fuel input. Diesel CV = 10,200 kcal/kg, sp.gr 0.85. Calculate the unaccounted loss as % of input energy.

70. A boiler uses 6 t/day coal (GCV 3300 kcal/kg, Rs 4200/t) at 72% efficiency. Coal is replaced by agro-residue (GCV 3100 kcal/kg, Rs 1800/t) at the same 72% efficiency. Calculate the annual cost savings for 300 days.

71. A gas-fired water heater heats water at 10 litre/min from 30 C to 95 C. GCV of gas = 4 x 10^4 kJ/kg, efficiency 60%, Cp water = 4.2 kJ/kg.C. Find the gas consumption in kg/min.

72. State the correct answers to the chapter's key objective recalls: (i) an example of stored mechanical energy; (ii) active power in an AC circuit; (iii) what nameplate kW/HP of a motor indicates; (iv) the fuel with the maximum difference between GCV and NCV.

73. In what unit is the rate of energy (heat) transfer from a higher to a lower temperature measured, and why?

74. Expand and briefly explain the common acronyms used in this chapter: GCV, NCV, PF, kVA, kVAR, MD, LF, TOD.

75. Define load factor and calculate it for a facility that consumed 900,000 kWh over a 30-day billing period with a peak demand of 2000 kW.

76. The rating of a single phase electric geyser is 2300 Watts, at 230 Volt. Calculate: a) Rated current b) Resistance of the geyser in Ohms c) Actual power drawn when the measured supply voltage is 210 Volts

77. The rating of a single phase electric geyser is 2000 Watts, at 230 Volt. Calculate: a) Rated current b) Resistance of the geyser in Ohms c) Actual power drawn when the measured supply voltage is 210 Volts

78. When the same quantity of heat is added to equal masses of iron and copper pieces, the temperature of iron piece rises by 15 oC. Calculate the rise in temperature of copper piece, if the specific heat of iron is 470 J/kg/oC and that of copper is 390 J/kg/oC.

79. The rating of a single phase electric geyser is 2000 Watts, at 230 Volt. Calculate: a) Rated current b) Resistance of the geyser in Ohms c) Actual power drawn when the measured supply voltage is 220 Volts

80. When the same quantity of heat is added to equal masses of iron and copper pieces, the temperature of iron piece rises by 20 oC. Calculate the rise in temperature of copper piece, if the specific heat of iron is 470 J/kg/oC and that of copper is 390 J/kg/oC.

81. Pressure of a nitrogen gas supplied to an oil tank for purging is measured as 100 mm of water gauge when barometer reads 756 mm of mercury. Determine the volume of 1.5 kg of this gas if it’s temperature is 25 0C. Specific gravity of mercury: 13.6. Take R = 8.3143 kJ/(kMol x K)

82. State true or false (each carries 1 mark): a) When it is raining, there is a substantial difference between the dry and wet bulb temperatures. b) The specific gravity of light diesel oil is given in kg/m3 c) The major constituent of LNG is propane d) Evaporative cooling of space requires use of refrigerant R134a e) HSD needs preheating to increase viscosity

83. In a textile plant monthly energy consumption is 7,00,000 kWh of electricity, 40 kL of furnace oil (specific gravity = 0.92) for thermic fluid heater, 360 tonne of coal for steam boiler and 10 kL of HSD (specific gravity = 0.885) for material handling equipment. Compute the energy consumption in terms of Metric Tonne of Oil Equivalent (MTOE) for the plant. Given Data: (1 kWh = 860 kcal, GCV of coal = 3450 kcal/kg, GCV of furnace oil = 10,000 kcal/kg, GCV of HSD = 10,500 kcal/kg, GCV of rice husk = 3100 kcal/kg, 1 kg oil equivalent = 10,000 kcal)

84. A water pumping station fills a tank at a fixed rate. The head and flow rate are constant and hence the power drawn by the pump is always same. The pump delivers 80 litres per second. The power consumption was measured as 84 kW. Calculate the energy consumption for pumping 2880 kL of water to the reservoir.

85. A furnace shell has to be cooled from 95 deg C to 45 deg C. The mass of the furnace shell is 4 tonnes. The specific heat of the furnace shell is 0.122 kcal/kg deg C. Water is available at 30 deg C. The maximum permissible increase in water temperature is 5 deg C. Ignoring the heat loss, compute the quantity of water required to cool the furnace. (5 Marks)

86. A 10 HP rated induction motor having name plate details of 415 V, 12 amps and 0.9 PF is being tested for an audit. Input measuring instrument display was showing 2 kVAr and PF of 0.758. Determine the percentage loading of the motor during the test. (5 Marks)

87. The rating of a single phase electric geyser is 2000 Watts, at 230 Volt. Calculate: a) Rated current (1 Mark) b) Resistance of the geyser in Ohms (1 Mark) c) Actual power drawn in kW when the measured supply voltage is 210 Volts (3 Marks)

88. A shell and tube heat exchanger is used to increase the temperature of furnace oil from a temperature of 60 deg C to 120 deg C using steam as the heating medium. The oil flow rate is 3500 kl/hr. The density of furnace oil is 0.89 kg/liter. Calculate the amount of steam required in t/hr to heat the furnace oil, if the specific heat of furnace oil is 0.5 kcal/kg deg C. The total enthalpy of steam is 2733 kJ/kg. The condensate is leaving the heat exchanger at 397 kJ/kg. (5 Marks)

89. A 10 HP rated induction motor, with nameplate details indicating 415V, 12 amps, and a power factor (PF) of 0.9, is being audited. During the audit, the monitoring equipment displays a reactive power of 2 kVAr and a power factor of 0.758. Calculate the percentage loading of the motor at the time of the test. (5 Marks)

90. A drilling machine drawing continuously 5 kW of input power and with an efficiency of 50%, is used in drilling a bore in an aluminum block of 5 kg of mass. A portion of energy imparted to the block is lost to surroundings and the balance is absorbed by the block in its uniform heating. A 45 deg C rise in temperature of the block was observed at the end of 100 seconds and the specific heat of aluminum block is 900 J/kgK. What percentage of drilling machine output power is lost to the surroundings? (5 Marks)

91. In a heat exchanger steam is used to heat 5 kL/hour of furnace oil from 30 deg C to 90 deg C. Specific heat of furnace oil is 0.22 kcal/kg deg C and the specific gravity of furnace oil is 0.95. a) How much steam per hour is required, if steam used is having latent heat of 510 kcal/kg? b) If steam cost is Rs. 3.40/kg and electrical energy cost is Rs. 6/kWh, which type of heating would be more economical in this particular case? (5 Marks)

92. A facility has a connected load of 500 kW and currently has a contract demand of 500 kVA. The monthly maximum demand recorded is consistently around 350 kW at 0.85 power factor. The utility imposes a penalty of Rs. 350 per excess kVA/month if recorded demand exceeds contract demand. The demand charge is Rs. 300 per kVA/month. a) Determine current demand in kVA. (1 Mark) b) The minimum billing demand is 80% of contract demand. Calculate excess demand charges paid above minimum billing demand per month. (2 Marks) c) Calculate minimum power factor required to avoid payment of excess demand charges over minimum billing demand. (2 Marks)

93. A food processing unit uses the following per day: LPG consumption 200 kg/day (CV = 11,000 kcal/kg, rate Rs. 90/kg); DG backup 100 kWh/day when the grid fails, using diesel at Rs. 95/litre with a specific fuel consumption of 260 ml/kWh (CV = 10,000 kcal/litre); Electrical energy 1,200 kWh/day at Rs. 7.5/kWh. Calculate (Each 1 Mark): a) Convert the LPG energy to kWh equivalent. b) Calculate the thermal energy input (in kcal) required by the DG to produce 100 kWh. c) Calculate the daily energy cost from all 3 sources. d) Calculate the percentage contribution of each energy source to the total energy input (in kWh equivalent). e) Determine the cost share of each energy source in the total energy cost and identify the most economic source among grid power, LPG and DG power.

1. Define and explain the following, giving the governing relation and its significance in energy management: (a) Specific heat; (b) Power factor. State the specific heat of water and the effect of a low power factor in an industry.

2. Define the following psychrometric terms and state the relationship between them: (a) Relative humidity; (b) Wet-bulb temperature; (c) Dew point. Also note the relation to dry-bulb temperature at 100% RH.

3. A 3-phase 10 kW motor has nameplate details 415 V, 18.2 A, 0.9 PF. During running, a power analyser measures 415 V, 12 A and 0.7 PF. Find the rated input power, the rated efficiency, the actual (measured) input power and the percentage motor loading.

4. State the relationship between power, voltage and current for balanced single-phase and three-phase AC loads. Then solve: (a) a 3-phase AC induction motor draws 440 V, 25 A at 0.90 PF - find the energy consumed in 1 hour; (b) a 400 W mercury-vapour lamp (230 V, 2 A, PF 0.8) runs 10 hours/day - find the energy consumption per day.

5. An electric heater rated 230 V, 5 kW is used for hot-water generation in an industry. Find the electricity consumption per hour (a) at the rated voltage and (b) if the supply voltage falls to 200 V. Explain the principle used.

6. Define latent heat, latent heat of fusion and latent heat of vaporization, and solve: (a) the heat given up by 10 kg of water at 0 degC when it freezes to ice at 0 degC (h_if = 335 kJ/kg); (b) the mass of ice melted when 20 kJ is supplied to ice at 0 degC; (c) the heat required to vaporize 2 m3 of water at 100 degC (h_fg = 2257 kJ/kg).

7. Determine the total heat required to convert 5 kg of water at 30 degC into dry saturated steam at 100 degC at atmospheric pressure. Take specific heat of water Cp = 4.2 kJ/kg degC and latent heat of vaporization h_fg = 2257 kJ/kg. Express the answer in kJ and in kcal.

8. A plant load is 500 kW at 0.75 power factor lagging. It is to be improved to 0.95 lagging by installing shunt capacitors. Calculate (a) the initial apparent power (kVA) and reactive power (kVAR); (b) the reactive power after correction; (c) the capacitor rating (kVAR) required; (d) the new kVA; and (e) the percentage reduction in apparent power (and hence line current). State the benefits of the improvement.

9. Explain the following electricity-tariff terms used in energy-cost management: (a) Maximum (contract) demand; (b) Load factor; (c) Time-of-Day (TOD) tariff; (d) Availability Based Tariff (ABT); (e) power-factor penalty/incentive. Then calculate the load factor of a continuously operating facility that consumed 900,000 kWh during a 30-day billing period with an established peak demand of 2000 kW.

10. Explain how the energy content (calorific value) of a fuel is determined using a bomb calorimeter. Distinguish between Gross Calorific Value (GCV) and Net Calorific Value (NCV), give typical values for heavy fuel oil, and state for which type of fuel the GCV - NCV difference is greatest and why.

11. Describe the three primary modes of heat transfer, explaining the mechanism and giving an example of each, and distinguish between forced and natural convection.

12. State and explain the three laws of thermodynamics. Relate the second law to entropy and explain why a heat engine can never be 100% efficient.

13. Working from the standard BEE energy-conversion values, solve: (a) convert 10 kWh (ten units) into kcal and into MJ; (b) convert a 50 HP motor rating into kW; (c) express 2500 kg of coal of GCV 4000 kcal/kg in tonnes of oil equivalent (toe); (d) express 125 tonnes of the same coal in toe.

14. Explain the enthalpy of steam and the terms specific enthalpy, dryness fraction and superheat. Give the specific enthalpy of saturated water, saturated steam and evaporation at standard atmospheric pressure, and distinguish the sensible and latent heat involved in generating steam.

15. (a) Explain the difference between GCV and NCV of a fuel. (b) A gas-fired water heater heats water flowing at 1.2 m3/hour from 20 degC to 65 degC. If the GCV of the gas is 4 x 10^7 J/kg and the efficiency of the water heater is 80%, find the rate of gas combustion in kg/hr. Take Cp of water = 4.187 kJ/kg degC and density of water = 1000 kg/m3.

16. A 15 kW, 415 V, 27 A, 4-pole, 50 Hz, 3-phase squirrel-cage induction motor has a full-load efficiency of 90% and PF 0.86. During operation a power analyser reads 406 V, 22 A, PF 0.82. Find (a) the input power in kW and (b) the percentage motor loading.

17. In a textile plant the average monthly energy consumption is 7,00,000 kWh of purchased electricity from grid, 40 kL of furnace oil (specific gravity = 0.92) for thermic fluid heater, 60 tonne of coal for steam boiler, and 10 kL of HSD (sp. gravity = 0.885) for material handling equipment. Given data: (1 kWh = 860 kcal, GCV of coal = 3450 kCal/kg, GCV of furnace oil = 10,000 kCal/kg, GCV of HSD = 10,500 kCal/kg, 1 kg oil equivalent = 10,000 kCal). a) Calculate the energy consumption in terms of Metric Tonne of Oil Equivalent (MTOE) for the plant. b) Calculate the percentage share of energy sources used based on consumption in MTOE basis. c) Comment whether this textile plant qualifies as a notified designated consumer under the Energy Conservation Act?

18. In a textile plant the average monthly energy consumption is 5,00,000 kWh of purchased electricity from grid, 40 kL of furnace oil (specific gravity = 0.92) for thermic fluid heater, 60 tonne of coal for steam boiler, and 10 kL of HSD (sp. gravity = 0.885) for material handling equipment. Given data: (1 kWh = 860 kcal, GCV of coal = 3450 kCal/kg, GCV of furnace oil = 10,000 kCal/kg, GCV of HSD = 10,500 kCal/kg, 1 kg oil equivalent = 10,000 kCal). a) Calculate the energy consumption in terms of Metric Tonne of Oil Equivalent (MTOE) for the plant. b) Calculate the percentage share of energy sources used based on consumption in MTOE basis. c) Comment whether this textile plant qualifies as a notified designated consumer under the Energy Conservation Act?

19. a. Explain the difference between GCV and NCV. b. A gas fired water heater heats water flowing at the rate of 1.2 M3/hour from 20 oC to 65 oC. If the GCV of the gas is 4 x 10^7 J/kg, what is the rate of combustion gas in kg/hr. The efficiency of water heater as 80%.

20. a. Explain the difference between GCV and NCV. b. A gas fired water heater heats water flowing at the rate of 1.2 M3/hour from 20 oC to 65 oC. If the GCV of the gas is 4 x 10^7 J/kg, what is the rate of combustion gas in kg/hr. The efficiency of water heater as 85%.

21. Explain the following a) Dry Bulb Temperature and Wet bulb Temperature b) Maximum Demand and Power Factor c) Gross Calorific Value & Net Calorific Value d) 5S & Return of Investment (ROI) e) CUSUM

22. A) Fill in the blanks: 1. The current drawn by an electric kettle having resistance of 25 Ohms and receiving supply at 250 Volts is ____. 2. In three-phase system kW will be equal to kVA if the power factor is ____. 3. The specific gravity of water is ____. 4. The change in heat content of a substance, when its physical state is changed without change in temperature is called ____ heat. 5. Specific heat of water is 1 kcal/kg deg C or ____ kcal/kg deg K. (5 Marks) B) Briefly explain PAT Scheme and list 5 sectors covered under the scheme. (5 Marks)