Power Plant Engineering Mcq Pdf Download

21. The function of moderator in a nuclear reactor is

(a) to absorb the excess neutrons.
(b) to increase the energy of the neutrons.
(c) to slow down the neutrons.

22. A moderator material should have

(a) small atomic mass.
(b) large atomic mass.
(c) none of the above.

23. Graphite is used in nuclear power plant as a

(a) fuel.
(b) coolant.
(c) moderator.
(d) electrode.

24. Which of the following materials cannot be used as a moderator ?

(a) Deuterium.
(b) Graphite.
(c) Heavy water.
(d) Beryllium.

25. Consider the following moderators used in nuclear reactors:

1. Graphite.
2. Beryllium.
3. Heavy water.

Their correct sequence in increasing order of their neutron absorption cross section is
(a) 1, 3, 2.
(b) 2, 1, 3.
(c) 3, 1, 2.
(d) 3, 2, 1.

26. Which material is used in controlling chain reaction in a nuclear reactor ?

(a) Thorium.
(b) Heavy water.
(c) Boron.
(d) Beryllium.

27. Control rods used in nuclear reactors are made of

(a) zirconium.
(b) boron.
(c) beryllium.
(d) lead.

28. In a nuclear reactor, chain reaction is controlled by introducing

(a) iron rods.
(b) cadmium rods.
(c) graphite rods.
(d) brass rods.

29. Heavy water is used in nuclear power plant as

(a) fuel.
(b) coolant.
(c) reflector.
(d) moderator.
(e) shield.
(f) both (b) and (d)

30. Which of the following materials can be used as a coolant ?

(a) Heavy water.
(b) CO₂
(c) Helium.
(d) Any of the above.

31. The function of reflector in a nuclear reactor is to

(a) bounce back most of the neutrons that escape from the fuel core.
(b) reduce the speed of the neutrons.
(c) stop the chain reaction.
(d) all of the above.

32. Reflectors of a nuclear reactor are made of

(a) cast iron.
(b) beryllium.
(c) steel.
(d) boron.

33. Thermal shielding is provided to

(a) absorb the fast neutrons.
(b) protect the operating personnel from exposure to radiations.
(c) prevent the reactor wall from getting heated.
(d) all of the above.

34. The radiation shield for a nuclear power reactor for biological safety is provided by having the reactor:

(a) immersed in water pool.
(b) encased by thick metal walls.
(c) encased by thick concrete wall.
(d) isolated from outside world with strong magnetic fields.

35. In boiler water reactor (BWR)

(a) the feed water acts both coolant and a moderator.
(b) enriched uranium is used as fuel.
(c) there is a danger of radioactive contamination of steam.
(d) all of the above.

36. Tarapur atomic power station has

(a) CANDU type reactors.
(b) boiling water reactors.
(c) pressurized water reactors.
(d) gas cooled reactors.

37. The thermal efficiency of a boiler water reactor is……..that of a pressurized water reactor.

(a) greater than.
(b) equal to.
(c) less than

38. In a pressurized water reactor (PWR)

(a) light or heavy water is used as both coolant and moderator.
(b) water is used at high pressure (as high as 140 kg/cm²) so that it is available in liquid form at about 280°C.
(c) the coolant water boils in the reactor core.
(d) both (a) and (b).

39. A CANDU reactor uses

(a) highly enriched uranium as fuel and light water as moderator and coolant.
(b) natural uranium as fuel and heavy water as moderator and coolant.
(c) enriched uranium as fuel and ordinary water as moderator and cooler.
(d) only fertile material.

40. Which one of the following is employed as a moderator by CANDU type of slow thermal nuclear reactors?

(a) Water.
(b) Heavy water.
(c) Graphite.
(d) Beryllium.