Power Plant Engineering Objective Questions And Answers

21. Fuel cells for power generation have the drawbacks of

(a) very high development costs.
(b) low service life and low voltage.
(c) noise, pollution and maintenance problems.
(d) both (a) or (b).

22. The disadvantage(s) of renewable sources of energy is/are

(a) intermittency.
(b) lack of dependability.
(c) availability in low energy densities.
(d) all of the above.

23. Biogas consists of

(a) only methane.
(b) methane and carbon dioxide with some impurities.
(c) only ethane.
(d) a special organic gas.

24. The main source(s) of production of biogas is /are

(a) wet cow dung.
(b) human waste.
(c) wet livestock waste.
(d) all of the above.

25. The main by-product of the biogas plant is

(a) biomass.
(b) biogas.
(c) organic manure.
(d) none of the above.

26. Biogas plants are suitable for

(a) metallurgical industries.
(b) commercial complexes.
(c) rural areas.
(d) coal mines.

27. The energy radiated by Sun on a bright sunny day is about

(a) 2.5 kW/m²
(b) 1.0 kW/m²
(c) 500 W/m²
(d) 200 W/m²

28. Most of solar radiations received on earth surface are within the range of

(a) 0.25 – 0.4 micron.
(b) 0.4 – 0.8 micron.
(c) 0.6 – 0.95 micron.
(d) 0.1 – 0.25 micron.

29. Which of the following area is preferred for solar plants ?

(a) Coastal areas.
(b) Hot arid zones.
(c) Mountain tops.
(d) High rainfall zones.

30. In solar power plants the solar heat is transferred to

(a) molten salts.
(b) liquid metals.
(c) water steam.
(d) any of the above.

31. Main applications of solar energy may be considered as

(a) direct thermal applications.
(b) fuel from biomass.
(c) solar-electric applications.
(d) all of the above.

32. Insulation is referred to as

(a) diffuse radiations received at any time.
(b) direct radiations received at any time.
(c) both of the above.
(d) none of the above.

33. Solar thermal power generation can be had by using

(a) flat plate collectors.
(b) focusing or concentrating collectors.
(c) solar ponds.
(d) any of the above.

34. The function of a solar collector is of converting solar energy into

(a) radiations.
(b) electrical energy directly.
(c) thermal energy.
(d) any of the above.

35. In a solar collector, the transparent cover is provided to

(a) protect the collector from dust.
(b) reduce the heat losses from collector beneath to atmosphere.
(c) transmit solar radiation only .
(d) all of the above.

36. Flat plate collector

(a) has plate blackened in order to absorb maximum amount of direct radiations.
(b) is placed at a proper inclination to the Sun so as to absorb solar radiations.
(c) is mainly used for water heating, space-heating, and drying.
(d) all of the above.

37. The flat plate collector gives a

(a) temperature of about 90°C with an efficiency of 30 – 35%.
(b) temperature of about 120°C with an efficiency of 45%.
(c) temperature of about 150°C with an efficiency of 52% .
(d) none of the above.

38. Temperature attained by cylindrical parabolic collector is of the order of

(a) 50 – 100°C
(b) 100 – 150°C
(c) 150 – 200°C
(d) 200 – 300°C and above.

39. Reflector mirrors employed for exploiting solar energy are called the

(a) mantle.
(b) heliostats.
(c) diffusers.
(d) ponds.

40. Sun tracking is required in case of

(a) cylindrical parabolic and paraboloid.
(b) flat plate collector.
(c) both (a) and (b).
(d) none of the above.