Electric Drives and Motors MCQ Part-10

1. Sometimes the wheels of the rotating machinery, in fluorescent tube lighting, appear to be stationary. This is due to________.

a. Stroboscopic effect

b. Light fluctuation

c. luminescence effect

d. All of the above

2. The flicker effect of fluorescent lamps is more pronounced at_______.

a. Higher voltages

b. Higher frequencies

c. Lower frequencies

d. Lower voltages

3. The frequency of flickers in a fluorescent tube operating at 220 V, 50 Hz supply is__________.

a. 25 per second

b. 50 per second

c. 100 per second

d. 200 per second

4. Standard wattage of 1 m fluorescent tube is___________.

a. 25 W

b. 65 W

c. 80 W

d. 100 W

5. Radio-interference from a fluorescent  tube can be reduced by________.

a. Putting two tubes in parallel

b. Connecting a small  capacitor across  starter terminals

c. Eliminating choke

d. Any of the above

6. In a mercury vapour lamp light, red objects appear black. This is on account of__________.

a. Absorption of red light by the lamp

b. Absence of red light from lamp radiations

c. High wavelength of red colour

d. Colour mixing

7. Blinking of fluorescent tube may be on account of__________.

a. Defective starter

b. Loose contact

c. Low circuit voltage

d. Any of the above

 

8. The cost of fluorescent tube is more than that of an incandescent lamp on account of_________.

a. More labour required

b. More quantity of glass in the tube 

c. More components in the tube

d. Any of the above

 

9. The lamp that gives nearly ultraviolet light is___________.

a. Argon gas filled filament lamp

b. Vacuum type filament lamp

c. Carbon arc lamp

d. All of the above

10. For the same wattage the cheapest lamp is_________.

a. Fluorescent lamp

b. Halogen lamp

c. GLS lamp

d. Sodium vapour lamp

11. The lamp that causes radio-interference is__________.

a. Mercury vapour lamp

b. Halogen lamp

c. Fluorescent tube

d. All of the above

12. The lamp that cannot be used for dimming is_________.

a. GLS lamp

b. Fluorescent lamp

c. Cold cathode lamp

d. All of the above

13. Floodlighting is not used for_________.

a. Aesthetic purposes

b. Advertising purposes

c. Industrial purposes

d. Any of the above

14. Illumination due to moon light is about___________.

a. 0.03 lumen/m²

b. 0.3 lumen/m²

c. 30-50 lumen/m²

d. 300-500 lumen/m²

15. Materials used for copper plating are________.

a. Copper nitrate and sulphuric acid

b. Copper carbonate and ammonium carbonate

c. Copper sulphate and nitric acid

d. Copper sulphate and sulphuric acid

 

16. In a refrigeration cycle, the flow of refrigerant is controlled by_________.

a. Evaporator

b. Condenser

c. Expansion valve

d. Compressor

17. ________ is used as refrigerant in a vapour absorption refrigerator.

a. Sulphur dioxide

b. Water

c. Freon

d. Aqua ammonia

 

18. Ammonia is preferred as a refrigeration in large commercial installation because_________.

a. It has low latent heat

b. It is relatively cheap

c. It has a low working pressure

d. It is non-toxic

19. In a vapour absorption system lithium bromide is used as______.

a. Cooling substance

b. Absorbent

c. Lubricant

d. Refrigerant

20. Which of the following motors is used in household refrigerators ?

a. Synchronous motor

b. Single phase induction motor

c. Reluctance motor

d. DC shunt motor

21. In a refrigerator, defrosting may be done by_________.

a. Placing trays of warm waters in the refrigerator

b. Stopping the compressor for a while

c. Opening the door of the refrigerator

d. Any of the above

 

22. Air-conditioning is the simultaneous control of _______ in a confined space.

a. Temperature, humidity, purity and movement of air

b. Air movement

c. Humidity

d. Temperature

23.______is a process which is generally used for summer air-conditioning.

a. Heating and dehumidification

b. Adiabatic cooling

c. Chemical dehumidification

d. Cooling with dehumidification

 

24. Air is dehumidified by________.

a. Chemical absorption

b. Cooling

c. Heating

d. Both (a) and (b)

 

25. Compared to individual systems, the central type air-conditioning system has________ overall efficiency.

a. Unpredictable

b. Same

c. Lower

d. Higher

 

26. Main traction systems used in India are those using________ locomotives.

a. Electric

b. Diesel-electric

c. Diesel engine

d. Steam engine

e. All of the above

 

• Electric Drives and Motors MCQ Part-1
• Electric Drives and motors MCQ Part-2
• Electric Drives and Motors MCQ Part-3
• Electric Drives and Motors MCQ Part-5
• Electric Drives and Motors MCQ Part-6
• Electric Drives and Motors MCQ Part-7
• Electric Drives and Motors MCQ Part-8
• Electric Drives and Motors MCQ Part-9