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LIght and Illumination

 LIght and Illumination

1. The illumination level at A class stations should be
  1. 20 lux
  2. 30 lux
  3. 40 lux
  4. 50 lux

d. 50 lux
2. The illumination level at B class stations should be
  1. 20 lux
  2. 30 lux
  3. 40 lux
  4. 50 lux

b. 30 lux
3. The illumination level at C class stations should be
  1. 20 lux
  2. 30 lux
  3. 40 lux
  4. 50 lux

a. 20 lux
4. Recommended no. of light points in type I (DR) quarter is
  1. 5
  2. 6
  3. 7
  4. 8

b. 6
5. Recommended no. of light points in type II quarter is
  1. 5
  2. 6
  3. 7
  4. 8

b. 6
6. Recommended no. of light points in type III quarter is
  1. 5
  2. 6
  3. 7
  4. 8

d. 8
7. Recommended no. of light points in type IV quarter is
  1. 8
  2. 9
  3. 10
  4. 11

c. 10
8. Recommended no. of light points in type IV spl. quarter is
  1. 11
  2. 12
  3. 13
  4. 14

c. 13
9. Recommended no. of fan points in type I quarter is
  1. 2
  2. 3
  3. 4
  4. 5

a. 2
10. Recommended no. of fan points in type II quarter is
  1. 2
  2. 3
  3. 4
  4. 5

a. 2
11. Recommended no. of fan points in type III quarter is
  1. 2
  2. 3
  3. 4
  4. 5

b. 3
12. Recommended no. of fan points in type IV quarter is
  1. 2
  2. 3
  3. 4
  4. 5

c. 4
13. Recommended no. of fan points in type IV spl. quarter is
  1. 2
  2. 3
  3. 4
  4. 5

d. 5
14. Recommended connected load for type I (DR) quarter is
  1. 1.36 kW
  2. 3.48 kW
  3. 4.17 kW
  4. 6.85 kW

a. 1.36 kW
15. Recommended connected load for type II quarter is
  1. 1.36 kW
  2. 3.48 kW
  3. 4.17 kW
  4. 6.85 kW

b. 3.48 kW
16. Recommended connected load for type III quarter is
  1. 1.36 kW
  2. 3.48 kW
  3. 4.17 kW
  4. 6.85 kW

c. 4.17 kW
17. Recommended connected load for type IV quarter is
  1. 1.36 kW
  2. 3.48 kW
  3. 4.17 kW
  4. 6.85 kW

d. 6.85 kW
18. Recommended connected load for type IV spl. quarter is
  1. 4.17 kW
  2. 6.85 kW
  3. 8.6 kW
  4. 11.85 kW

c. 8.6 kW
19. Recommended connected load for type V quarter is
  1. 4.17 kW
  2. 6.85 kW
  3. 8.6 kW
  4. 11.85 kW

d. 11.85 kW
20. Luminous efficiency of a fluorescent tube is
  1. 10 lumens/ watt
  2. 20 lumens/ watt
  3. 40 lumens/ watt
  4. 60 lumens/ watt

d. 60 lumens/ watt
21. Candela is the unit of which of the following?
  1. wavelength
  2. luminous intensity
  3. luminous flux
  4. frequency

b. luminous intensity
22. Colour of light depends upon
  1. frequency
  2. wave length
  3. both (a) and (b)
  4. speed of light

c. both (a) and (b)
23. Illumination of one lumen per sq. metre is called ………
  1. lumen metre
  2. lux
  3. foot candle
  4. candela

b. lux
24. The unit of luminous flux is …………
  1. watt/ m2
  2. lumen
  3. lumen/ m2
  4. watt

b. lumen
25. Filament lamps operate normally at a power factor of
  1. 0.5 lagging
  2. 0.8 lagging
  3. unity
  4. 0.8 leading

c. unity
26. What percentage of the input energy is radiated by filament lamps?
  1. 2 to 5 percent
  2. 10 to 15 percent
  3. 25 to 30 percent
  4. 40 to 50 percent

a. 2 to 5 percent
27. The filament of a GLS lamp is made of
  1. tungsten
  2. copper
  3. carbon
  4. aluminium

b. copper
28. Which of the following lamps is the cheapest for the same wattage?
  1. Fluorescent tube
  2. mercury vapour lamp
  3. GLS lamp
  4. sodium vapour lamp

c. GLS lamp
29. Which of the following is not the standard rating of GLS lamps?
  1. 100 W
  2. 75 W
  3. 40 W
  4. 15 W

b. 75 W
30. The colour of sodium vapour discharge lamp is
  1. red
  2. pink
  3. yellow
  4. bluish green

c. yellow
31. A reflector is provided to
  1. protect the lamp
  2. provide better illumination
  3. avoid glare
  4. do all of the above

d. do all of the above
32. The purpose of coating the fluorescent tube from inside with white power is
  1. to improve its life
  2. to improve the appearance
  3. to change the colour of light emitted to white
  4. to increase the light radiations due to secondary emissions

d. to increase the light radiations due to secondary emissions
33. In the fluorescent tube circuit the function of choke is primarily to
  1. reduce the flicker
  2. minimize the starting surge
  3. initiate the arc and stabilize it
  4. reduce the starting current

c. initiate the arc and stabilize it
34. The function of capacitor across the supply to the fluorescent tube is primarily to
  1. stabilize the arc
  2. reduce the starting current
  3. improve the supply power factor
  4. reduce the noise

c. improve the supply power factor
35. Most affected parameter of a filament lamp due to voltage change is
  1. wattage
  2. life
  3. luminous efficiency
  4. light output

b. life
36. In electric discharge lamps for stabilizing the arc
  1. a reactive choke is connected in series with the supply
  2. a condenser is connected in series to the supply
  3. a condenser is connected in parallel to the supply
  4. None

a. a reactive choke is connected in series with the supply
37. For precision work the illumination level required is of the order of
  1. 500 – 1000 lumens/m²
  2. 200 – 400 lumens/m²
  3. 50 – 100 lumens/ m²
  4. 10 – 25 lumens/ m²

a. 500 – 1000 lumens/m²
38. For normal reading the illumination level required is around
  1. 20 – 40 lumens/ m²
  2. 60 – 100 lumens/ m²
  3. 200 – 300 lumens/ m²
  4. 400 – 500 lumens/ m²

b. 60 – 100 lumens/ m²
39. In electric discharge lamps light is produced by
  1. cathode ray emission
  2. ionization in a gas or vapour
  3. heating effect of current
  4. magnetic effect of current

b. ionization in a gas or vapour
40. A substance which change its electrical resistance when illuminated by light is called…..
  1. photoelectric
  2. photovoltaic
  3. photoconductive
  4. none of the above

c. photoconductive
41. In case of … power factor is the highest.
  1. GLS lamps
  2. mercury arc lamps
  3. tube lights
  4. sodium vapour lamps

a. GLS lamps
42. A mercury vapour lamp gives … light.
  1. white
  2. pink
  3. yellow
  4. greenish blue

d. greenish blue
43. Sometimes the wheels f rotating machinery, under the influence of fluorescent lamps appear to be stationary. This is due to the
  1. low power factor
  2. stroboscopic effect
  3. fluctuations
  4. luminescence effect

b. stroboscopic effect
44. The flicker effect of fluorescent lamps is more pronounced at
  1. lower frequencies
  2. higher frequencies
  3. lower voltages
  4. higher voltages

a. lower frequencies
45. Which gas can be filled in GLS lamp?
  1. oxygen
  2. carbon di-oxide
  3. xenon
  4. any inert gas

d. any inert gas
46. The gas filled in vacuum filament lamps is
  1. nitrogen
  2. argon
  3. air
  4. none

d. none
47. The vapour discharge tube used for domestic lighting has
  1. no filament
  2. one filament
  3. two filament
  4. three filament

c. two filament
48. Stroboscopic effect due to use of discharge lamps in workshops results in moving machinery appearing
  1. stationary
  2. stationary running slow
  3. stationary running in reverse direction
  4. all of the above

d. all of the above
49. Glare is reduced by
  1. using diffusers
  2. increasing the height of the lamp
  3. using reflectors to cut-off the light at certain angle
  4. all of the above

d. all of the above
50. Which of the following is present inside the fluorescent tube?
  1. argon and neon
  2. argon and CO2
  3. mercury vapour
  4. helium and oxygen

c. mercury vapour
51. When an electric bulb is broken it produces bang; this is due to
  1. vacuum inside the bulb
  2. pressure of air in the bulb
  3. pressure inside is equal to that outside
  4. None

a. vacuum inside the bulb

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