100 Important Illumination MCQ Question and Answer | PDF Free Download
1.For normal reading the illumination level required is around
- A20 ? 40 lumens/sq. metre
- B60 ? 100 lumens/sq. metre
- C200 ? 300 lumens/sq. metre
- D400 ? 500 lumens/sq. metre
2.Light is produced In electric discharge lamps by
- ACathode ray emission
- BIonisation in a gas or vapour
- CHeating effect of current
- DMagnetic effect of current
3.A substance which change its electrical resistance when illuminated by light is called
- APhotoelectric
- BPhotovoltaic
- CPhotoconductive
- DNone of the above
4.In case of ___________ power factor is the highest.
- AGLS lamps
- BMercury arc lamps
- CTube lights
- DSodium vapour lamps
5.A mercury vapour lamp gives _____________ light.
- AWhite
- BPink
- CYellow
- DGreenish blue
6.Sometimes the wheels of rotating machinery, under the influence of fluorescent lamps appear to be stationary. This is due to the
- ALow power factor
- BStroboscopic effect
- CFluctuations
- DLuminescence effect
7.Which of the following bulbs operates on least power?
- AGLS bulb
- BTorch bulb
- CNeon bulb
- DNight bulb
8.The flicker effect of fluorescent lamps is more pronounced at
- ALower frequencies
- BHigher frequencies
- CLower voltages
- DHigher voltages
9.Which of the following applications does not need ultraviolet lamps?
- ACar lighting
- BMedical purposes
- CBlue print machines
- DAircraft cockpit dashboard lighting
10.Which gas can be filled in GLS lamps?
- AOxygen
- BCarbon dioxide
- CXenon
- DAny inert gas
11.The gas filled in vacuum filament lamps is
- ANitrogen
- BArgon
- CAir
- DNone
12.Luminous flux is
- AThe light energy radiated by sun
- BThe part of light energy, radiated by sun, which is received on the earth
- CThe rate of energy radiation in the form of light waves
- DNone of the above
13.The vapour discharge tube used for domestic lighting has
- ANo filament
- BOne filament
- CTwo filaments
- DThree filaments
14.In an incandescent lamp bird cage filament is usually used in vacuum bulb so as to
- AReduce the oxidation phenomenon
- BReduce the convection losses
- CHave uniform radiations
- DIncrease the life span of the filament
15.Stroboscopic effect due to use of discharge lamps in workshops results in moving machinery appearing
- AStationary
- BStationary running slow
- CStationary running in reverse direction
- DAll of the above
16.Co-efficient of utilisation depends upon
- AColour of the walls
- BColour of ceiling
- CSize of the room
- DAll of the above
17.Glare is reduced by
- AUsing diffusers
- BIncreasing the height of the lamp
- CUsing reflectors to cut-off the light at certain angle
- DAll of the above
18.Which of the following is present inside the fluorescent tube?
- AArgon and neon
- BArgon and Carbon dioxide
- CMercury vapour
- DHelium and oxygen
19.When an electric bulb is broken it produces bang because
- AVacuum inside the bulb
- BPressure of air in the bulb
- CPressure inside is equal to that outside
- DNone of the above
20.Due to which of the following reasons the light of a tube appears cooler than that of a bulb?
- ATungsten is not used in the tube
- BTube is painted with milky colour
- CTube consumer less power
- DSurface area of the tube is more than that of bulb