Objective Questions on Illumination for Electrician Trade
| Sr. No. | Questions with options |
| 1 | What is the S.I unit of luminous intensity?
(a) Lux (b) Lumen (c) Candela (d) Steradian Ans-(c) |
| 2 | What is the working temperature of filament lamp?
(a) 1500 degree Celsius (b) 1800 degree Celsius (c) 2000 degree Celsius (d) 2300 degree Celsius Ans –(d) |
| 3 | Which material is coated in tungsten electrode of a fluorescent tube lamp?
(a) Silver oxide (b) Phosphor powder (c) Fluorescent powder (d) Barium and stroatium oxide Ans – (d) |
| 4 | Which position MB type high pressure mercury vapor lamps are operated?
(a) Vertical (b) Inclined (c) Horizontal (d) Any position Ans- (d) |
| 5 | What is the function of leak transformer in high pressure sodium vapor lamp circuit?
(a) Reduce the starting current (b) Reduce the working voltage (c) Increase the working voltage (d) Ignite the high voltage initially Ans – (d) |
| 6 | How stroboscopic effect in industrial twin tube light fitting is reduced?
(a) Connecting capacitor parallel to supply (b) Connecting capacitor in series with supply (c) Connecting capacitor in series with one tube light (d) Connecting two capacitors in series to each tube light Ans- (c) |
| 7 | Which term refers that the flow of light into a plane surface?
(a) Lumen (b) Illuminance (c) Luminous flux (d) Luminous intensity Ans – (b) |
| 8 | What is the purpose of ignitor in high pressure sodium vapor lamp circuit?
(a) Decreases the starting current (b) Increases the running voltage (c) Decreases the running current (d) Generates high voltage pulse at starting Ans –(d) |
| 9 | Which type of light fitting design has free from glare?
(a) Semi direct type (b) Semi indirect type (c) Direct lighting type (d) Indirect lighting type Ans – (b) |
| 10 | Why the outer tube of a high pressure metal halide lamp made of boro silicate glass?
(a) Increase the lighting effect (b) Withstand heavy temperature (c) Withstand atmospheric pressure (d) Reduce the ultra violet radiation from lamp Ans – (d) |
| 11 | What is the term refers luminous flux given by light source per unit solid angle?
(a) Lumen (b) Candela (c) Illuminance (d) Luminous intensity Ans – (d) |
| 12 | What is the unit of luminous flux?
(a) Lux (b) Lumen (c) Candela (d) Lumen/ sq.meter Ans – (b) |
| 13 | What is the unit of luminous efficiency?
(a) Lux (b) Lumen (c) Lumen/meter square (d) Lumen/watt Ans – (d) |
| 14 | How the rate of evaporation in a vacuum bulb is reduced?
(a) Filling inert gas (b) Producing arc in bulb (c) Reducing filament resistance (d) Increasing filament resistance Ans- (a) |
| 15 | What is the main advantage of coiled coil lamp?
(a) High melting point (b) Higher light output (c) Low operating voltage (d) Low power consumption Ans – (b) |
| Published On – 4th June 2022 | |
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