WorksheetsFUEE_ELECTRIC LIGHTING
Total questions: 40
Worksheet time: 20mins
Candela is the unit of which?
Wavelength
Luminous Intensity
Luminous Flux
Frequency
Solid angle is expressed in terms of
Radians/meter
Radians
Steradians
Degree
Which lamp has the best Colour Rendering Index (CRI)?
LED
Fluorescent
Incandescent
High Pressure Sodium Vapour
Which lamps can be directly connected to a solar cell?
Incandescent
LED
Sodium vapor lamp
Compact Flurescent
Candela/metre square is the unit of which quantity?
Illuminance
Luminous Flux
Luminance
Luminous Intensity
Which lamp is best suited for lighting an International sports arena?
Incandescent
Sodium vapor lamp
Compact Fluorescent
LED
What is the work of a driver in case of an LED?
To convert AC to DC
To convert DC to AC
Both A and B
None of these
What will be the number of lamps, each having 300 lumens, required to obtain an average illuminance of 50 lux on a 4m × 3m rectangular room?
2
4
5
6
The range of visual spectrum is
300nm - 1000nm
480nm - 1000nm
480nm - 760nm
300nm - 760nm
What will be the total flux emitted by a source of 60 candle power?
754.2 lumens
0.001326 lumens
60 lumens
None of these
The solid angle subtended by an area of 2400 cm2 on the surface of a sphere of diameter 1.2 m is
3/2
1/3
2/3
2/5
In illumination technology total lumens emitted by source / total lumens available after waste of light is equal to
Waste Light Factor
Utilization Factor
Beam Factor
Absorption Factor
The illumination at a point 5 meters below a lamp is 6 lux. The candle power of the lamp is
30
140
150
200
Which among the following lamps has the maximum burning hours?
LED
Incandescent
Sodium vapor lamp
Compact Fluroscent
Illumination can be expressed in
Radians
Lux
Lumens
Candela
The choke in tube light wiring provides
High impulse voltage
High current
High resistance
Low resistance
A 60W lamp, given a luminous flux of 1500 lumen will have an efficiency of
1500 lumen/watt
250 lumen/watt
25 lumen/watt
2.5 lumen/watt
An instrument which is used to measure the level of illuminations is
Power Analyser
Synergy Meter
Multimeter
Lux meter
A 50 watt incandescent bulb remains 'ON' for an average of 10 hours a day for a week. The total energy consumed expressed in kilowatt hours is
3.5
0.35
50
35
Which of the following lamps has the shortest/less life span in working hours?
Sodium vapor lamp
Fluorescent lamp
Mercury vapor lamp
Incandescent lamp
Lamp efficiency is measured in
lumen/watt
lumen/lux
candela/watt
lux/watt
For indoor lighting the ratio of space : height is
3:4
5:6
1:2
2:3
Polar curves represent the
distribution of the brightness in all directions
distribution of luminous intensity of light source in all directions
distribution of luminous flux in all directions
distribution of Illuminance in all directions
The total quantity of light energy emitted per second from a luminous body is defined as
Luminous flux
Light
Light flux density
Luminous intensity
The function of inert gas in filament lamp is
Increase the illumination
Decreases the power consumption
Minimize the effect of evaporation during service
Decrease the clear
Radiant efficiency of a luminous source depends on
Shape of the source
Temperature of the source
Wave length of light rays
All are correct
CFL means
Combustible fluoride lamp
Compact fluoride lamp
Compact fluorescent lamp
Combustible fluorescent lamp
In fluorescent lamp one capacitor is connected across the lamp circuit and another is connected across the starter. Then
Both the capacitors are used for improving power factor
Both the capacitors are used for reducing radio interference
Former capacitors is used for improving power factor and later is used for reducing radio interference
Former capacitors is used for reducing radio interference and later is used for improving power factor
The main electrode of high pressure mercury vapour lamp is made up of
Quartz
Hard Glass
Tungsten
Bronze
Maintenance factor is the ratio of
Lumens on the working plane under normal working conditions to the lumens on the working plane under ideal condition
Lumens on the working plane under ideal working conditions to the lumens on the working plane under normal condition
Lumens falling on the working plane to the lumens emitted by the working plane under ideal condition
Lumens emitting by the working plane to the lumens falling on the working plane under ideal condition
For best visual performance, the range of brightness within the field of vision
Should be less than 3:1
Should be greater than 3:1
Should be less than 1:3
Should be greater than 1:3
The inside wall of fluorescent tube is coated with
Sulphur powder
Phosphor powder
Sodium
Krypton
Nitrogen is added with the argon in an incandescent lamp to
Reduce the temperature
Reduce the possibility of arcing
Increase the brightness
Increase the efficiency
The artificial source of light is
Arc lamp
Incandescent lamp
Discharge lamp
All of these
The polar curves are used to find out the
MHCP
MSCP
Both
None
According to the first law of illumination, the illumination of a surface due to a source of light is
Inversely proportional to the distance between the surface and the source of light
Inversely proportional to the square of the distance between the surface and the source of light
Directly proportional to the distance between the surface and the source of light
Directly proportional to the square of the distance between the surface and the source of light
Reduction factor of a source of light is the ratio of its
Mean horizontal candle power to the mean spherical candle power
Mean spherical candle power to the mean horizontal candle power
Maximum horizontal candle power to the mean spherical candle power
Mean spherical horizontal candle power to the maximum spherical candle power
Flood lighting is used for
For enhancing the beauty of building at nights
For illuminating sports stadium
For illuminating show cases
All of these
The illumination due to good daylight is approximately equal to
100 lux
200 lux
300 lux
400 lux
A bulb has a power of 200W. What is the energy dissipated by it in 5 minutes?
60J
1000J
60kJ
1kJ
