106. Glow lamps
(A) have cold cathode
(B) have hot cathode
(C) cannot withstand shocks
(D) consume high power
107. 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
108. 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
109. Which of the following glass transmits the maximum light?
(A) Serrated glass
(B) Opalescent glass
(C) Clear glass
(D) Milk glass
110. Which of the following glass transmits the least amount of light?
(A) Clear glass
(B) Serrated glass
(C) Milk glass
(D) Opalescent glass
111. 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
112. E-40 caps are generally used for GLS lamps of wattage above
(A) 25 W
(B) 100W
(C) 300W
(D) 1000 W
113. 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
114. 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.
115. Halogen lamps are useful for the illumination of
(A) Sports grounds
(B) Parks
(C) Airports
(D) All of the above.
116. 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.
117. The light output of fluorescent lamps is around
(A) 10 lumens/watt
(B) 20 lumens/watt
(C) 70 lumens/watt
(D) 200 lumens/watt.
118. Which of the following is preferred for air conditioned spaces?
(A) GLS lamp
(B) Fluorescent tube
(C) Mercury vapor lamp
(D) Sodium vapor lamp.
119. The normal life span of a fluorescent lamp is
(A) 500 hours
(B) 1000 hours
(C) 1500 hours
(D) 7500 hours.
120. The color of light depends on
(A) wavelength
(B) frequency
(C) wavelength and frequency
(D) wavelength, frequency speed and intensity
