60+ most frequently asked Illumination Engineering (IE) mcq for exams and interviews. Illumination Engineering mcq with answers that can help you to crack online exams and interviews. These IE mcq also includes nptel mcq questions of electrical Electrical Engineering.
Illumination Engineering mcq
Q. 71. According to Lambert’s law, the illumination on a surface is proportional to
A : cos2θ
B : cos3θ
C : 1/cos3θ
D : 1/ cos2θ.
cos3θ
Q. 72. A lamp has a mean spherical candle power of 25, the total flux of light from the lamp is
A : 25 lumens
B : 25 π lumens
C : 314 lumens
D : 625 lumens.
314 lumens
Q. 73. Which of the following material can be used for the filaments in incandescent lamps is
A : carbon
B : tungsten
C : tantalum
D : any of the above.
any of the above.
Q. 74. The melting point of carbon is
A : 1800°C
B : 2200°C
C : 3500°C
D : 5500° C.
3500°C
Q. 75. Which of the following filament material has the lowest melting point ?
A : Carbon
B : Tungsten
C : Tantalum
D : Osmium.
Osmium.
Q. 76. The operating characteristics of an incandescent lamp arc materially affected by departure from its normal operating voltage. The total number of lumens given out by the lamp increases with the increase in operating voltage and the relation between them is : Lumens output α Vn where n is a constant. The value of n for tungsten varies for
A : 0.5 to 0.75
B : 1.5 to 2.5
C : 4 to 5
D : 8 to 10
4 to 5
Q. 77. Filament lamps operate normally at a power factor of
A : 0.5 leading
B : 0.5 lagging
C : unity
D : 0.8 lagging.
unity
Q. 78. Neon gas in sodium vapor lamp
A : changes the color of light
B : acts as a shield around the filament
C : assists in developing enough heat to vaporize the sodium
D : prevents vaporization of filament.
assists in developing enough heat to vaporize the sodium
Q. 79. Which of the following is a cold cathode lamps ?
A : Sodium vapor lamp
B : High pressure mercury vapor lamp
C : Low pressure mercury vapor lamp
D : Neon lamp.
Neon lamp.
Q. 80. In fluorescent tubes ballast resistance is connected in series with the choke
A : when supply frequency is low
B : to reduce radio interference
C : when tube operates on dc supply
D : to reduce stroboscope effects.
when tube operates on dc supply
Q. 81. While comparing tungsten filament lamps with fluorescent tubes, all of the following are the advantages in favor of tungsten filament lamp EXCEPT
A : Longer life
B : Less costly
C : More brightness
D : Simple installation.
Longer life
Questions 83 to 85 refer to data given below: The 220 V lamps, one of 60 W and the other of 75 W arc connected in series across a 440 V supply.
Q. 82. The potential difference across 60 W lamp will be
A : 195 V
B : 220 V
C : 245 V
D : 440 V.
245 V
Q. 83. The potential difference across 75 watt lamp will be
A : 195 V
B : 220 V
C : 245 V
D : 440 V.
195 V
Q. 84. Assuming candle power to be proportional to fourth power of the voltage, the candle power of 60 W lamps under above conditions as a percentage of its value under normal operation at 220 V will be
A : 110%
B : 1549%
C : 220%
D : 440%.
1549%
Q. 85. Which of the following lamp has last capacity to sustain voltage fluctuations ?
A : sodium vapor lamp
B : fluorescent lamp
C : incandescent lamp
D : mercury vapor lamp.
incandescent lamp
Q. 86. In neon signs argon gas is used for
A : yellow color
B : blue color
C : red color
D : green color.
red color
Q. 87. In neon signs, helium is used for
A : yellow color
B : green color
C : red color
D : blue co lour.
yellow color
Q. 88. In neon signs, neon with a mixture of mercury gives
A : green color
B : blue color
C : red color
D : yellow color.
green color
Q. 89. The electrodes of neon tubes work at
A : very low temperatures
B : ordinary voltages
C : 400 to 440 volts
D : 2000 to 6000 volts.
2000 to 6000 volts.
Q. 90. Glare may result from
A : excessive lighting contrast in the field of vision
B : excessive luminance
C : either of A : or B : above
D : none of the above
either of A : or B : above
Q. 91. To avoid glare
A : object should be viewed from a distance
B : object should be viewed from a close vicinity
C : object should be moved constantly
D : viewer should move constantly.
object should be viewed from a distance
Q. 92. The light output of GLS lamps is normally in the range
A : 10 to 18 lumens/watt
B : 50 to 80 lumens/watt
C : 100 to 180 lumens/watt
D : 200 to 300 lumens/watt.
10 to 18 lumens/watt
Q. 93. Nitrogen or argon is filled in GLS lamps to
A : reduce the glare
B : improve efficiency
C : change the color of light
D : retard evaporation of tungsten filament.
retard evaporation of tungsten filament.
Q. 94. In case of frosted GLS lamps, frosting of shell is done by
A : ozone
B : ammonia
C : acid etching
D : salt water.
acid etching
Q. 95. The luminous flux reaching the working plane least depends on
A : the lumen output of the lamps
B : proportion of the room
C : reflectance of internal surfaces
D : color of the working plane surface.
color of the working plane surface.
Q. 96. Which of the following lamp gives nearly monochromatic light ?
A : Sodium vapor lamp
B : GLS lamp
C : Tube light
D : Mercury vapor lamp.
Sodium vapor lamp
Q. 97. Materials which reflect all wavelengths in the light spectrum appear to be
A : black to white
B : transparent
C : opaque
D : green to red.
black to white
Q. 98. An object which appears red to the eyes, absorbs
A : green radiations
B : blue radiations
C : violet radiations
D : all of the above.
all of the above.
Q. 99. Glare is the result of
A : very low luminance
B : normal luminance
C : excessive luminance
D : none of the above.
excessive luminance
Q. 100. Glow lamps
A : have cold cathode
B : have hot cathode
C : cannot withstand shocks
D : consume high power.
have cold cathode
Q. 101. The illumination required for normal reading is around
A : 500 lumens/m2
B : 300 – 400 lumens/m2
C : 100 – 250 lumens/m2
D : 60 – 100 lumens/m2
500 lumens/m2
Q. 102. Which of the following surface has the lowest reflection factor for white light ?
A : Aluminium sheet
B : White plaster work
C : Blue curtains
D : White oil paint
Blue curtains
Q. 103. Which of the following glass transmits the maximum light ?
A : Serrated glass
B : Opalescent glass
C : Clear glass
D : Milk glass.
Clear glass
Q. 104. Which of the following glass transmits the least amount of light?
A : Clear glass
B : Serrated glass
C : Milk glass
D : Opalescent glass.
Milk glass
Q. 105. B-15 size cap for GLS lamp indicates that
A : cap diameter is 15 mm
B : cap is screw type
C : cap is made of brass
D : cap is filled by cement.
cap diameter is 15 mm
Q. 106. E-40 caps arc generally used for GLS lamps of wattage above
A : 25 W
B : 100W
C : 300W
D : 1000 W.
300W
Q. 107. In case of GLS lamps as the supply voltage increases, which of the following decreases ?
A : Lumen output
B : Power consumption
C : Life
D : Efficiency.
Life
Q. 108. The advantage of halogen lamp is
A : no depreciation of light output
B : increased operating temperature with increased luminous efficiency
C : reduced dimensions of the lamp
D : all of the above.
all of the above.
Q. 109. Halogen lamps are useful for the illumination of
A : Sports grounds
B : Parks
C : Airports
D : All of the above.
All of the above.
Q. 110. Coating or fluorescent lamps
A : converts ultra-violet, radiations into visible light
B : converts visible light into ultra-violet radiations
C : reduces glare
D : none of the above.
converts ultra-violet, radiations into visible light
Q. 111. The light output of fluorescent lamps is around
A : 10 lumens/watt
B : 20 lumens/watt
C : 70 lumens/watt
D : 200 lumens/watt.
70 lumens/watt
Q. 112. Which of the following is preferred for air conditioned spaces ?
A : GLS lamp
B : Fluorescent tube
C : Mercury vapor lamp
D : Sodium vapor lamp.
Fluorescent tube
Q. 113. The normal life span of a fluorescent lamp is
A : 500 hours
B : 1000 hours
C : 1500 hours
D : 7500 hours.
7500 hours.
Q. 114. The color of light depends on
A : wavelength
B : frequency
C : wavelength and frequency
D : wavelength, frequency speed and intensity.
wavelength and frequency
Q. 115. The disadvantage of fluorescent lamps as compared to GLS lamps is
A : noise in choke
B : stroboscope effect
C : high cost
D : all of the above.
all of the above.
Q. 116. In case of a fluorescent lamp if only the ends of the lamp remain lighted it indicates
A : a short circuited starter
B : a defective choke
C : a defective lube
D : defective wiring.
a short circuited starter
Q. 117. Blinking of a fluorescent tube may be due to
A : low circuit voltage
B : low ballast rating
C : low temperature
D : any of the above.
any of the above.
Q. 118. Radio interference generally results due to
A : GLS lamps
B : Halogen lamps
C : Fluorescent lamps
D : Sodium lamps.
Fluorescent lamps
Q. 119. A fluorescent tube can be operated on
A : AC only
B : DC only
C : Both AC as well as DC.
D :
Both AC as well as DC.
Q. 120. The ignition voltage for sodium lamps is
A : 100 to 150 volts .
B : 200 to 220 volts
C : 400 to 440 volts
D : 400 to 600 volts.
400 to 600 volts.
Q. 121. A leak transformer is provided with
A : frosted GLS lamps
B : high wattage GLS lamps
C : fluorescent lamps
D : sodium lamps.
sodium lamps.
Q. 122. Leak transformer in sodium lamps initially provides
A : low voltage
B : high current
C : high voltage
D : none of the above.
high voltage
Q. 123. The color of sodium lamp is
A : blue
B : yellow
C : red
D : white.
yellow
Q. 124. Sodium lamps are used for:
A : reading rooms
B : street lights
C : auditoria
D : libraries.
libraries.
Q. 125. The average life of sodium lamps is around
A : 1000 hours
B : 2500 hours
C : 6000 hours
D : 12000 hours.
6000 hours
Q. 126. High pressure mercury vapor light contains
A : yellow color
B : bluish white color
C : red color
D : white color.
bluish white color
Q. 127. The average life high pressure mercury vapor lamps is
A : 500 hours
B : 1000 hours
C : 9000 hours
D : 20,000 hours.
9000 hours
Q. 128. High pressure mercury vapor lamps are generally used in
A : factories
B : railway yards
C : shopping centers
D : all of the above.
all of the above.
Q. 129. A substance which changes its electrical resistance when illuminated by light is called
A : photovoltaic
B : photoelectric
C : photo-conductive
D : none of the above.
photo-conductive
Q. 130. Wavelength for blue color
A : 4400 A
B : 5250 A
C : 6150 A
D : 5950 A.
4400 A
Q. 131. Radio interference from a fluorescent lamp can be reduced by
A : putting two lamps in parallel
B : eliminating choke
C : putting a capacitor across the lamp
D : none of the above.
putting a capacitor across the lamp
Q. 132. Dimming systems for lights are used in
A : theatres
B : auditoriums
C : ball room
D : all of the above.
all of the above.
Q. 133. Which of the following can be used as a light dimming device ?
A : Auto transformer
B : Variable reaction
C : SCR
D : Any of the above.
Any of the above.
Q. 134. Which of the following is difficult to adopt for dimming ?
A : GLS lamps
B : Cold cathode lamps
C : Fluorescent lamps
D : All of the above.
Fluorescent lamps
Q. 135. Heat from light source is particularly of importance while
A : designing for illumination level
B : designing for floor space utilization
C : designing for air conditioning
D : all of the above.
designing for air conditioning
Q. 136. In electric discharge lamps for stablizing the arc
A : a condenser is connected in parallel to supply
B : a condenser is connected in series to supply
C : a variable resistor is connected in the circuit
D : a reactive choke is connected in series with supply.
a variable resistor is connected in the circuit
Q. 137. The lens of the eye to focuses an image on the
A : corona
B : membrane
C : calorie
D : retina.
retina.
Q. 138. The sensors in the eye arc known as
A : rods and cones
B : wires and nerves
C : retina and antenna
D : high and low.
rods and cones