Mercury Vapour Lamp Multiple Choice Questions and Answers
36. The luminous efficiency of high-pressure mercury vapour lamps ranges from ........lumens/watt
A. 30 to 40
B. 70 to 90
C. 100 to 120
D. 150 to 180
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A. 30 to 40
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37. A Mercury vapour lamp gives light of
A. Green colour light
B. Pink colour light
C. Greenish blue colour light
D. White colour light
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38. High-pressure mercury vapour lamps
A. Are similar in construction to sodium vapour lamps
B. Need four or five minutes to attend a full brilliancy
C. Are generally used for general industrial lighting railway yards etc.
D. All of the above
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39. High-pressure Mercury vapour lamps
A. The main electrodes are made of tungsten wire in the form of helix
B. The choke is provided to limit the current to a safe value
C. In addition to two main electrodes a starting electrode is connected through a high resistance
D. All of the above
E. None of the above
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40. Which off the following lambs is a cold cathode lamp ?
A. Sodium vapour lamp
B. Mercury vapour lamp
C. Neon lamp
D. None of the above
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