Power Electronics mcq objective questions and answers part2

Q1. Pressure of steam in condenser is
(A) atmospheric pressure
(B) more than pressure
(C) slightly less than pressure
(D) much less than pressure.

Q2. In a power plant, coal is carried from storage place to boilers generally by means of
(A) bucket
(B) V-belts
(C) trolleys
(D) manually.

Q3. Heating value of coal is approximately
(A) 1000-2000 kcal / kg
(B) 2000-4000 kcal / kg
(C) 5000-6500 kcal / kg
(D) 9000-11000kcal / kg.

Q4. What is Pulverized coal
(A) coal free from ash
(B) non-smoking coal
(C) coal which bums For long time
(D) coal broken into fine particles.

Q5. The value of the reheat factor is of the order of
(A) 0.6 to 1.0
(B) 1.0 to 1.05
(C) 1.1 to 1.5
(D) above 1.5

Q6. Bucket elevators are used for
(A) carrying coal in horizontal direction
(B) carrying coal in vertical direction
(C) carrying coal in any direction
(D) All of these

Q7. Primary air is that air which is used to
(A) reduce the flame length
(B) increase the flame length
(C) transport and dry the coal
(D) None of these

Q8. The capacity of large turbo-generators varies from
(A) 20 to 100 MW
(B) 50 to 300 MW
(C) 70 to 500 MW
(D) 100 to 650 MW

Q9. Which of the following material can be used as a moderator ?
(A) Graphite
(B) Heavy water
(C) Beryllium
(D) Any of the above

Q10. Major constituent of methane gas is
(A) CO
(B) methane
(C) Nitrogen
(D) hydrogen

Q11. For the safety of a steam boiler the number of safety valves fitted are
(A) four
(B) three
(C) two
(D) one

Q12. In a surface condenser if air is removed, there is
(A) fall in absolute pressure maintained in condenser
(B) rise in absolute pressure maintained in condenser
(C) no change in absolute pressure in the condenser
(D) rise in temperature of condensed steam

Q13. Which of the following methods is used for governing Steam turbines
(A) Throttle governing
(B) Nozzle control governing
(C) By-pass governing
(D) all of the above

Q14. Steam engine used in locomotive is
(A) single acting, condensing type
(B) single acting, non-condensing type
(C) double acting, non-condensing type
(D) double acting, condensing type

Q15. The efficiency of a thermal power plant improves with
(A) increased quantity of coal burnt
(B) larger quantity of water used
(C) lower load in the plant
(D) use of high steam pressures.

Q16. The efficiency of a modern boiler using coal and heat recovery equipment is about
(A) 10 to 30%
(B) 40 to 50%
(C) 60 to 70%
(D) 85 to 90%

Q17. Curtis turbine is a
(A) reaction steam turbine
(B) pressure velocity compounded steam turbine
(C) pressure compounded impulse steam turbine
(D) velocity compounded impulse steam turbine

Q18. The critical pressure ratio of a convergent nozzle is defined as the ratio of
(A) outlet pressure to inlet pressure of nozzle
(B) inlet pressure to outlet pressure of nozzle
(C) outlet pressure to inlet pressure only when mass flow rate per unit area is minimum
(D) outlet pressure to inlet pressure only when mass flow rate = c

Q19. Diesel engine fuels are rated by
(A) Octane number
(B) H.U.C.R.
(C) Cetane number
(D) CRF number.

Q20. Which one of the following is an advantage of hydro-electric power station
(A) low operating cost
(B) free from pollution problems
(C) no fuel transportation problems
(D) all of the above