MCQ Questions on Generation of Electrical Power

1. The secondary sources of energy are

(a) Solar, wind and water
(b) Coal, oil and uranium
(c) Either (a) or (b)
(d) Neither (a) or (b)

2. The draught which a chimney produces is called

(a) Induced draught
(b) Natural draught
(c) Forced draught
(d) Balanced draught

3. The draught in locomotive boilers is produced by

(a) Forced fan
(b) Chimney
(c) Steam jet
(d) Only motion of locomotive

4. Caking coals are those which

(a) Burn completely
(b) Burn freely
(c) Do not form ash
(d) Form lumps or masses of coke

5. Blowing down of boiler water is the process

(a) To reduce the boiler pressure
(b) To increase the steam temperature
(c) To control the solid concentration in the boiler water by removing some of the concentrated saline water
(d) None of the above

6. The blades of the gas turbine rotor are made of

(a) Carbon steel
(b) Stainless steel
(c) High alloy steel
(d) High nickel alloy (Nimic 80)

7. Fission chain reaction is possible when

(a) Fission produces the same number of neutrons which are absorbed
(b) Fission produces more neutrons than are absorbed
(c) Fission produces less neutrons than are absorbed
(d) None of the above

8. A consumer has to pay lesser fixed charges in

(a) Flat rate tariff
(b) Two part tariff
(c) Maximum demand tariff
(d) None of the above

9. In Hopkinson demand rate or two part tariff the demand rate or fixed charges are

(a) Dependent upon the energy consumed
(b) Dependent upon the maximum demand of the consumer
(c) Both (a) and (b)
(d) None of the above

10. In a load-duration curve for an integrated power system the uppermost crest represents the energy contributed by

(a) Base power station
(b) Major thermal station
(c) Peaking hydro or gas turbine stations
(d) Non-conventional power stations

11. The voltage of a single solar cell is

(a) 0.2 V
(b) 0.5 V
(c) 1.0 V
(d) 2.0 V

12. Load curve is useful in deciding the

(a) Operating schedule of generating units
(b) Sizes of generating units
(c) Total installed capacity of the plant
(d) All of the above

13. Annual operating expenditure of a power plant consists of

(a) Fixed charges
(b) Semi-fixed charges
(c) Running charges
(d) All of the above

14. Direct conversion of heat into electric power is possible through

(a) Fuel cell
(b) Batteries
(c) Thermionic converter
(d) All of the above

15. A pilot exciter is provided on generators for which of the following reasons?

(a) To excite the poles of main exciter
(b) To provide requisite starting torque to main exciter
(c) To provide requisite starting torque to generator
(d) None of the above

16. The maximum demand of a consumer is 2 kW and his daily energy consumption is 20 units. His load factor is

 (a) 10%
(b) 41.6%
(c) 50%
(d) None of the above

17. The economizer, a component of steam power plants, is a heat-exchanger utilising the waste heat of

(a) Bleed-steam to heat the feed water
(b) Flue-gas to heat the feed water
(c) Flue-gas to heat the air going into the boiler
(d) Flue-gas to heat the pulverised coal

18. In electrical energy which type of tariff is also called as Doherty rate? [MP JE 2016]

(a) Block rate tariff
(b) Flat part tariff
(c) Two part tariff
(d) Three part tariff

19. In a load curve, the highest point represents the

(a) Average Load
(b) Base Load
(c) Diversified Load
(d) Peak Load

20. The instantaneous power taken by a balanced three-phase load supplied from a balanced three phase source is

(a) Zero
(b) A constant value
(c) A pulsating function with a non-zero average
(d) Alternating with a zero average

21. To increase power transfer capability of a long transmission line, we should

(a) Increase line resistance
(b) Increase transmission voltage
(c) Decrease line reactance
(d) Both (b) & (c)

22. The moderator is used in nuclear power plant to

(a) prevent the reactor from harmful radiation
(b) increase the speed of neutron
(c) decrease the speed of neutron
(d) coolent

23. Lignite, bituminous and anthracite are different ranks of

(a) Nuclear fuel
(b) Coal
(c) Biogas
(d) Natural gas

24. In a nuclear reactor, heavy water can be ideally used as

(a) Biological shield
(b) Moderator
(c) Control rods
(d) All of the above

25. Value of Power factor lies in between

(a) 0 and 1
(c) 10 and 100
(b) 0 and 10
(d) 10 and 1000

26. Which of the following is a device capable of supplying electrical energy?

(a) Microwave
(c) Solar cell
(b) Radio transmitter
(d) None of these

27. Large turbo-generators are usually driven by

(a) Coal turbine
(b) Steam turbine
(c) Diesel turbine
(d) Water turbine

28. What is the maximum possible output of a solar array?

(a) 500 W/m²
(b) 250 W/m²
(c) 500 kW/m²
(d) 250 mW/m²

29. If maximum load of generating station and the rated plant capacity are equal then

(a) Load factor is 1
(b) Capacity factor is 1
(c) Load factor and capacity factor are equal
(d) Utilization factor is poor. [UPPCL JE – 2014]

30. Which of the following expressions depicts the Utilization Factor?

(a) Ratio of maximum generator demand to the generator capacity.
(b) Ratio of actual energy produced to the generator capacity.
(c) Ratio of generator capacity to maximum generation demand.
(d) Ratio of generator capacity to actual energy produced.

31. In a star connected balanced circuit the phase difference between the line voltage V_RY and the phase voltage V_RN is equal to

(a) 30° – φ
(b) 60°
(c) 120°
(d) 30°

32. The following generating station has the minimum running cost

(a) Diesel power station
(b) Nuclear power station
(c) Hydroelectric power station
(d) Thermal power station

33. The normal phase sequence of a 3 phase AC supply is

(a) RBY
(b) RYB
(c) BRY
(d) YBR [NMRC JE 2017]

34. The ratio of average load to the maximum demand during a given period is

(a) Demand factor
(b) Diversity factor
(c) Load factor
(d) Connected load

35. In a nuclear power station, moderator is used to

(a) Accelerate the speed of neutrons
(b) Stop the chain reaction
(c) Absorb neutrons
(d) Reduce the speed of neutrons

36. To a star connected 3 phase system, relationship between line voltage and phase voltage is given by

(a) V_L = V_ph
(b) V_L = 3V_ph
(c) V_L = √3 V_ph
(d) VL = √2 V_ph

37. Induced draft fans are located at

(a) The top
(b) The bottom
(c) In the middle part
(d) Can be anywhere, in the cooling tower

38. The disadvantages of renewable source of energy is /are

(a) Intermittency
(b) Lack of dependability
(c) Availability in low energy densities
(d) All the above

39. Which of the following is usually not the generating voltage

(a) 6.6 kV
(b) 11 kV
(c) 12.5 kV
(d) 13.2 kV

40. Large size steam power plants and nuclear plants are suitable for

(a) Base loads
(b) Intermediate loads
(c) Peak loads
(d) Both base and peak loads

41. Which plant can be never have 100% load factor

(a) Nuclear power plant
(b) Peak load plant
(c) Hydro electric power plant
(d) Base load plant

42. More heat loss in a steam power station occurs in

(a) Boiler
(c) Economiser
(b) Super heater
(d) Condenser

43. Which factor is a ratio of the sum of the individual maximum demands of the various subsystems of a system to the maximum demand of the whole system? [MP JE 2016]

(a) Capacity factor
(b) Diversity factor
(c) Demand factor
(d) Load factor

44. Which of the following connections of a three phase transformer are best suited for 3-phase, 4-wire service? [UPPCL JE – 2007]

(a) Δ – Δ
(b) Y – Y
(c) Δ – Y
(d) Y – Δ

45. Kaplan turbines are used whenever the water head is

(a) low
(b) high
(c) medium
(d) both (b) and (c)

46. Economisers are used to heat

(a) Coal
(b) Air
(c) Steam
(d) Feed water [UPPCL JE – 2007]

47. In thermal power plants, the pressure of working fluid cycle is developed by

(a) Condenser
(b) Superheater
(c) Feed water pump
(d) Turbine [UPPCL JE – 2007]

48. A gas turbine power plant is best suited for

(a) Base load
(b) Peak load
(c) Emergency purpose
(d) None of the above

49. Out of the following plant categories

 (i) Nuclear
(ii) Run-off river
(iii) Pump storage
(iv) Diesel
The base load power plants are
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i), (ii) and (iii)
(d) (i), (iii) and (iv) [UPPCL JE – 2007]

50. Which of the following components is not a part of hydro-electric plant? [UPPCL JE – 2007]

(a) Penstock
(b) Spillway
(c) Surge tank
(d) Economiser