Q61. | A mercury vapour lamp gives ____ light. | ||||||
A. | white [Wrong Answer] |
B. | pink [Wrong Answer] |
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C. | yellow [Wrong Answer] |
D. | greenish blue [Correct Answer] |
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Q62. | In an incandescent lamp bird cage filament is usually used in vacuum bulb so as to | ||||||
A. | reduce the oxidation phenomenon [Wrong Answer] |
B. | reduce the convection losses [Wrong Answer] |
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C. | have uniform radiations [Correct Answer] |
D. | increase the life span of the filament [Wrong Answer] |
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Q63. | Soft shadows are produced by | ||||||
A. | using surface source of light instead of point source of light [Wrong Answer] |
B. | increasing the number of lamps [Wrong Answer] |
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C. | both (a) and (b) [Correct Answer] |
D. | none of the above [Wrong Answer] |
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Q64. | Fine diameter tungsten wires are made by | ||||||
A. | turning [Wrong Answer] |
B. | swaging [Wrong Answer] |
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C. | compressing [Wrong Answer] |
D. | wire drawing [Correct Answer] |
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Q65. | On which of the following factors does the depreciation or maintenance factor depend ? | ||||||
A. | Lamp cleaning schedule [Wrong Answer] |
B. | Ageing of the lamp [Wrong Answer] |
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C. | Type of work carried out at the premises [Wrong Answer] |
D. | All of above [Correct Answer] |
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Q66. | Due to moonlight, illumination is nearly | ||||||
A. | 3000 lumens/m2 [Wrong Answer] |
B. | 300 lumens/m2 [Wrong Answer] |
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C. | 30 lumens/m2 [Wrong Answer] |
D. | 0.3 lumen/m2 [Correct Answer] |
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Q67. | In electric discharge lamps for stabilizing the arc | ||||||
A. | a reactive choke is connected in series with the supply [Correct Answer] |
B. | a condenser is connected in series to the supply [Wrong Answer] |
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C. | a condenser is connected in parallel to the supply [Wrong Answer] |
D. | a variable resistor is connected in the circuit [Wrong Answer] |
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Q68. | Sometimes the wheels ofrotating machinery, under the influence of fluorescent lamps appear to be stationary. This is due to the | ||||||
A. | low power factor [Wrong Answer] |
B. | stroboscopic effect [Correct Answer] |
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C. | fluctuations [Wrong Answer] |
D. | luminescence effect [Wrong Answer] |
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Q69. | Stroboscopic effect due to use of discharge lamps in workshops results in moving machinery appearing | ||||||
A. | stationary [Wrong Answer] |
B. | stationary running slow [Wrong Answer] |
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C. | stationary running in reverse direction [Wrong Answer] |
D. | all of the above [Correct Answer] |
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Q70. | Reflectors are provided with slits at the top to | ||||||
A. | introduce chimney effect for cleaning [Wrong Answer] |
B. | reduce colour contrast [Wrong Answer] |
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C. | reduce heating effect [Wrong Answer] |
D. | do all of the above functions [Correct Answer] |
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