electrical engineering Mcqs
1. economics of power generation2. analog electronics3. solid state switching circuits4. parallel circuits5. switchgear and protection6. op amp circuits7. transistor audio power amplifiers8. electrostatics9. heating and welding10. multi stage transistor amplifiers11. passive filters12. network theorems13. regulated d c power supply14. a c fundamentals circuits and circuit theory15. electromagnetic induction16. power electronics17. magnetism and electromagnetism18. transformers19. modulation and demodulation20. d c generators21. semiconductor theory22. single phase induction motors23. semiconductor diode24. hybrid parameters25. digital electronics26. oscillators27. earthing or grounding28. single stage transistor amplifiers29. d c motors30. transistor biasing31. amplifiers with negative feedback32. basic electrical33. electronic instruments34. synchronous motors35. field effect transistors fet36. magnetic circuit37. control systems38. industrial drives39. power generation40. series parallel circuits41. transistor tuned amplifiers42. electrical engineering materials43. rectifiers and converters44. integrated circuits45. scr silicon controlled rectifiers46. cables47. polyphase induction motors48. measurement and instrumentation49. transistors50. electrical machine design51. electrolysis and storage of batteries52. electric traction53. transmission and distribution
6351. For forced draught system, the function of chimney is mainly_____________?
comments icon0

A. to produce draught to accelerate the combustion of fuel

B. to reduce the temperature of the hot gases discharged

C. none of the above

D. to discharge gases high up in the atmosphere to avoid hazard
6352. In a regenerative surface condenser_____________?
comments icon0

A. there are three pumps to remove air, vapour and condensate

B. there are two pumps to remove air and condensate

C. there is no pump, the condensate gets removed by gravity

D. there is one pump to remove air and condensate

6353. Load center in a power station is___________?
comments icon0

A. center of coal fields

B. center of gravity of electrical system

C. center of maximum load of equipments

6354. For the same draught produced the power of induced draught fan as compared to forced draught fan is___________?
comments icon0

A. not predictable

B. less

C. same

D. more
6355. Reheat factor in steam turbines depends on______________?
comments icon0
A. initial pressures and temperature only

B. stage efficiency only

C. exit pressure only

D. all of the above

6356. Curtis turbine is_____________?
comments icon0

A. velocity compounded impulse steam turbine

B. pressure compounded impulse steam turbine

C. reaction steam turbine

D. pressure velocity compounded steam turbine
6357. The maximum percentage gain in Regenerative feed heating cycle thermal efficiency____________?
comments icon0

A. none of the above

B. increases with number of feed heaters increasing

C. remains same unaffected by number of feed heaters

D. decreases with number of feed heaters increasing

6358. The pressure on the two sides of the impulse wheel of a steam turbine_____?
comments icon0

A. increases from one side to the other side

B. is different

C. is same

D. decreases from one side to the other side

6359. Incase of reaction steam turbine___________?
comments icon0
A. there is enthalpy drop both in fixed and moving blades

B. there is enthalpy drop only in fixed blades

C. there is enthalpy drop only in moving blades

D. none of the above

6360. The draught produced by steel chimney as compared to that produced by brick chimney for the same height is_____________?
comments icon0

A. same

B. less

C. more

D. may be more or less

6361. Belt conveyer can be used to transport coal at inclinations upto____________?
comments icon0

A. 60

B. 90

C. 80

D. 30
6362. Secondary air is the air used to______________?
comments icon0

A. increase the flame length

B. reduce the flame length

C. provide air round the burners for getting optimum combustion

D. transport and dry the coal

6363. The efficiency of a modern boiler using coal and heat recovery equipment is about_____________?
comments icon0

A. 25 to 30%

B. 40 to 50%

C. 85 to 90%

D. 65 to 70%

6364. In jet type condensers___________?
comments icon0

A. steam and cooling water do not mix

B. cooling water passes through tubes and steam surrounds them

C. steam passes through tubes and cooling water surrounds them

D. steam and cooling water mix
6365. For Parsons reaction steam turbine, degree of reaction is____________?
comments icon0

A. 60%

B. 50%

C. 75%

D. 100%

6366. In a shell and tube surface condenser____________?
comments icon0
A. cooling water passes through the tubes and steam surrounds them

B. all of the above varying with situation

C. steam and cooling water mix to give the condensate

D. steam passes through the cooling tubes and cooling water surrounds them

6367. In a regenerative feed heating cycle, the greatest economy is affected___________?
comments icon0

A. when steam is extracted from only one suitable point of steam turbine

B. when steam is extracted only from the last stage of steam turbine

C. when steam is extracted only from the first stage of steam turbine

D. when steam is extracted from several places in different stages of steam turbine
6368. The maximum length of a screw conveyer is about___________?
comments icon0

A. 100 metres

B. 30 metres

C. 60 metres

D. 40 metres

6369. The draught in locomotive boilers is produced by_____________?
comments icon0

A. forced fan

B. only motion of locomotive

C. steam jet

D. chimney

6370. In a steam power plant, the function of a condenser is__________?
comments icon0

A. to condense large volumes of steam to water which may be used again in boiler

B. to maintain pressure below atmospheric to increase work output from the primemover

C. to receive large volumes of steam exhausted from steam prime mover

D. all of the above
6371. Rateau steam turbine is______________?
comments icon0
A. pressure compounded impulse steam turbine

B. velocity compounded impulse steam turbine

C. pressure velocity compounded steam turbine

D. reaction steam turbine

6372. The percentage O2 by Weight in atmospheric air is____________?
comments icon0

A. 77%

B. 23%

C. 79%

D. 18%

6373. In fuel cell, the ___________ energy is converted into electrical energy?
comments icon0

A. heat

B. mechanical

C. chemical

D. sound

6374. Pipes carrying steam are generally made up of_____________?
comments icon0

A. aluminium

B. cast iron

C. steel

D. copper

6375. The energy radiated by sun on a bright sunny day is approximately______________?
comments icon0

A. 700 W/m2

B. 800 W/m2

C. 1 kW/m2

D. 2 kW/m2

6376. Economisers improve boiler efficiency by__________?
comments icon0

A. 10 to 12%

B. 4 to 10%

C. 1 to 5%

6377. In a surface condenser if air is removed, there is___________?
comments icon0

A. rise in absolute pressure maintained in condenser

B. rise in temperature of condensed steam

C. no change in absolute pressure in the condenser

D. fall in absolute pressure maintained in condenser
6378. Bucket elevators are used for___________?
comments icon0

A. carrying coal in horizontal direction

B. carrying coal in any direction

C. carrying coal in vertical direction
6379. Steam turbines are governed by the following methods_____________?
comments icon0
A. all of the above

B. Nozzle control governing

C. By-pass governing

D. Throttle governing

6380. The critical pressure ratio of a convergent nozzle is defined as_____________?
comments icon0
A. the ratio of outlet pressure to inlet pressure only when mass flow rate = c

B. the ratio of outlet pressure to inlet pressure of nozzle

C. the ratio of outlet pressure to inlet pressure only when mass flow rate per unit area is minimum

D. the ratio of inlet pressure to outlet pressure of nozzle

6381. Steam turbines commonly used in steam power station are__________?
comments icon0

A. none of the above

B. non-condensing type

C. condensing type
6382. Artificial draught is produced by______________?
comments icon0

A. induced fan

B. induced and forced fan

C. all of the above

D. forced fan

6383. The overall efficiency of thermal power plant is equal to____________?
comments icon0

A. Boiler efficiency x turbine efficiency x generator efficiency

B. Rankine cycle efficiency

C. Carnot cycle efficiency

D. Regenerative cycle efficiency
6384. The modern steam turbines are___________?
comments icon0
A. impulse-reaction turbines

B. reaction turbines

C. none of the above

D. impulse turbines

6385. The commercial sources of energy are____________?
comments icon0

A. solar, wind and biomass

B. none of the above

C. wood, animal wastes and agriculture wastes

D. fossil fuels, hydropower and nuclear energy
6386. In Rankine cycle the work output from the turbine is given by__________?
comments icon0
A. change of enthaply between inlet and outlet

B. change of internal energy between inlet and outlet

C. change of entropy between inlet and outlet

D. change of temperature between inlet and outlet

6387. Binaryvapour cycles are used to_____________?
comments icon0

A. increase the performance of the condenser

B. increase the efficiency of the plant

C. increase efficiency of the turbine

6388. The efficiency of chimney is approximately______________?
comments icon0

A. 80%

B. 0.25%

C. 20%

D. 40%

6389. A steam power station requires space______________?
comments icon0

A. less than diesel power station

B. equal to diesel power station

C. more than diesel power station
6390. Blowing down of boiler water is the process_____________?
comments icon0

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

6391. Reheat cycle in steam power plant is used to________________?
comments icon0
A. increase thermal efficiency

B. reduce loss of heat

C. utilise heat of flue gases

D. improve condenser performance

6392. TravelUng grate stoker can burn coals at the rates of____________?
comments icon0

A. 75100 kg/m per hour

B. 150200 kg/m2 per hour

C. 5075 kg/m per hour

D. 100150 kg/m per hour

6393. The draught produced, for a given height of the chimney and given mean temperature of chimney gases_______________?
comments icon0

A. increases with increase in outside air temperature

B. may increase or decrease with increase in outside air temperature

C. decreases with increase in outside air temperature

D. remains the same irrespective of outside air temperature

6394. Artificial draught is produced by____________?
comments icon0
A. all of the above

B. steam jet

C. air fans

D. fan or steam jet

6395. Reheat factor is the ratio of_____________?
comments icon0

A. adiabatic heat drop to isentropic heat drop

B. isentropic heat drop to useful heat drop

C. cumulative actual enthalpy drop for the stages to total is isentropic enthalpy heat drop
6396. For the induced draught the fan is located_______________?
comments icon0

A. anywhere permissible

B. at the top of the chimney

C. near bottom of furnace

D. near bottom of chimney
6397. Rankine cycle operating on low pressure limit of p1 an 1 high pressure limit of p2__________?
comments icon0

A. may be more or less depending upon the magnitude of p1 and p2

B. has higher the renal efficiency than the carnot cycle operating between same pressure limits

C. has same thermal efficiency as carnot cycle operating between same pressure limits

D. has lower thenal efficiency than carnot cycle operating between same pressure limit?

6398. Example of overfeed type stoker is___________?
comments icon0
A. all of the above

B. spreader

C. travelling grate

D. chain grate

6399. In a boiler installation the natural draught is produced_____________?
comments icon0
A. due to the fact that pressure at the grate due to cold column is higher than the pressure at the chimney base due to hot column

B. all of the above

C. due to the fact that at the chimney top the pressure is more than its environmental pressure

D. due to the fact that furnace gases being light go through the chimney giving place to cold air from outside to rush in

6400. In De Laval steam turbine___________?
comments icon0

A. none from the above

B. the pressure in the turbine rotor is approximately same as in condenser

C. the pressure in the turbine rotor is higher than pressure in the condenser

D. the pressure in the turbine rotor gradually decreases from inlet to exit from condenser