Illumination What is the ratio of illuminance at a point 5m just below a lamp emitting 100 candelas and at a point 5m away from the first point on the same horizontal plane? 2√2 : 1 1: 2√2 1:2 2:1 2√2 : 1 1: 2√2 1:2 2:1 ANSWER DOWNLOAD EXAMIANS APP
Illumination The work of ballast in a fluorescent tube is to limit the flow of current. None of these. both ‘a’ and ‘b’. provide a kick start when voltage is induced. limit the flow of current. None of these. both ‘a’ and ‘b’. provide a kick start when voltage is induced. ANSWER DOWNLOAD EXAMIANS APP
Illumination What will be the number of lamps, each having 300 lumens, required to obtain an average illuminance of 50 lux on a 4m × 3m rectangular room? 4 6 5 2 4 6 5 2 ANSWER DOWNLOAD EXAMIANS APP
Illumination A 200 candle power lamp is hung 4 m above the centre of circular area of 5 m diameter. The illumination at centre of the area is 13.5 lux. 18.5 lux. 17.5 lux. 12.5 lux. 13.5 lux. 18.5 lux. 17.5 lux. 12.5 lux. ANSWER DOWNLOAD EXAMIANS APP
Illumination Luminous efficacy of a typical HPSV lamp is in between 70 - 120 lm/watt. 10 - 40 lm/watt 40 - 70 lm/watt. 120 - 200 lm/watt. 70 - 120 lm/watt. 10 - 40 lm/watt 40 - 70 lm/watt. 120 - 200 lm/watt. ANSWER DOWNLOAD EXAMIANS APP
Illumination The solid angle subtended by an area of 2400 cm2 on the surface of a sphere of diameter 1.2 m is 1 / 3. 2 / 3. 3 / 2. 2 / 5. 1 / 3. 2 / 3. 3 / 2. 2 / 5. ANSWER DOWNLOAD EXAMIANS APP
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