Electric Illumination MCQs

91. 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.

Answer
Answer. C

92. In neon signs argon gas is used for

(A) yellow colour
(B) blue colour
(C) red colour
(D) green colour

Answer
Answer. C

93. In neon signs, helium is used for

(A) yellow colour
(B) green colour
(C) red colour
(D) blue colour.

Answer
Answer. A

94. In neon signs, neon with a mixture of mercury gives

(A) green colour
(B) blue colour
(C) red colour
(D) yellow colour

Answer
Answer. A

95. The electrodes of neon tubes work at

(A) very low temperatures
(B) ordinary voltages
(C) 400 to 440 volts
(D) 2000 to 6000 volts

Answer
Answer. D

96. 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

Answer
Answer. C

97. 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

Answer
Answer. A

98. 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

Answer
Answer. A

99. 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

Answer
Answer. D

100. In case of frosted GLS lamps, frosting of shell is done by

(A) ozone
(B) ammonia
(C) acid etching
(D) salt water

Answer
Answer. C

101. 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.

Answer
Answer. D

102. Which of the following lamp gives nearly monochromatic light?

(A) Sodium vapor lamp
(B) GLS lamp
(C) Tube light
(D) Mercury vapor lamp

Answer
Answer. A

103. Materials which reflect all wavelengths in the light spectrum appear to be

(A) black to white
(B) transparent
(C) opaque
(D) green to red

Answer
Answer. A

104. An object which appears red to the eyes, absorbs

(A) green radiations
(B) blue radiations
(C) violet radiations
(D) all of the above

Answer
Answer. D

105. Glare is the result of

(A) very low luminance
(B) normal luminance
(C) excessive luminance
(D) none of the above.

Answer
Answer. C