Q51. | The purpose of coating the fluorescent tube from inside with white power is | ||||||
A. | to improve its life [Wrong Answer] |
B. | to improve the appearance [Wrong Answer] |
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C. | to change the colour of light emitted to white [Wrong Answer] |
D. | to increase the light radiations cl,ie to secondary emissions [Correct Answer] |
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Q52. | In sodium vapour lamp the function of the leak transformer is | ||||||
A. | to stabilize the arc [Wrong Answer] |
B. | to reduce the supply voltage [Wrong Answer] |
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C. | both (a) and (b) [Correct Answer] |
D. | None of above [Wrong Answer] |
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Q53. | In case of ____ power factor is the power factor is the | ||||||
A. | GLS lamps [Correct Answer] |
B. | mercury arc lamps [Wrong Answer] |
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C. | tube lights [Wrong Answer] |
D. | sodium vapour lamps [Wrong Answer] |
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Q54. | The vapour discharge tube used for domestic lighting has | ||||||
A. | no filament [Wrong Answer] |
B. | one filament [Wrong Answer] |
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C. | two filaments [Correct Answer] |
D. | three filaments [Wrong Answer] |
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Q55. | A poor man for his kitchen will make use of | ||||||
A. | fluorescent tube [Wrong Answer] |
B. | incandescent lamp [Correct Answer] |
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C. | sodium vapour lamp [Wrong Answer] |
D. | high pressure mercury vapour lamp [Wrong Answer] |
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Q56. | Luminous efficiency of a fluorescent tube is | ||||||
A. | 10 lumens/watt [Wrong Answer] |
B. | 20 lumens/watt [Wrong Answer] |
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C. | lumens/watt [Wrong Answer] |
D. | 60 lumens/watt [Correct Answer] |
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Q57. | The filament of a GLS lamp is made of | ||||||
A. | tungsten [Correct Answer] |
B. | copper [Wrong Answer] |
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C. | carbon [Wrong Answer] |
D. | aluminium [Wrong Answer] |
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Q58. | Desired illumination level on the working plane depends upon | ||||||
A. | age group of observers [Wrong Answer] |
B. | whether the object is stationary or moving [Wrong Answer] |
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C. | size of the object to be seen and its distance from the observer [Wrong Answer] |
D. | whether the object is to be seen for longer duration or shorter duration of time [Wrong Answer] |
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E. | all above factors [Correct Answer] |
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Q59. | _____ will need lowest level of illumination | ||||||
A. | Audiotoriums [Wrong Answer] |
B. | Railway platform [Correct Answer] |
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C. | Displays [Wrong Answer] |
D. | Fine engravings [Wrong Answer] |
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Q60. | Most affected parameter of a filament ‘lamp due to voltage change is | ||||||
A. | wattage [Wrong Answer] |
B. | life [Correct Answer] |
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C. | luminous efficiency [Wrong Answer] |
D. | light output [Wrong Answer] |
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