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? 1: 2√2 1:2 2√2 : 1 2:1 1: 2√2 1:2 2√2 : 1 2:1 ANSWER DOWNLOAD EXAMIANS APP
Illumination Luminous efficacy of a typical HPSV lamp is in between 70 - 120 lm/watt. 10 - 40 lm/watt 120 - 200 lm/watt. 40 - 70 lm/watt. 70 - 120 lm/watt. 10 - 40 lm/watt 120 - 200 lm/watt. 40 - 70 lm/watt. ANSWER DOWNLOAD EXAMIANS APP
Illumination The work of ballast in a fluorescent tube is to provide a kick start when voltage is induced. both ‘a’ and ‘b’. limit the flow of current. None of these. provide a kick start when voltage is induced. both ‘a’ and ‘b’. limit the flow of current. None of these. ANSWER DOWNLOAD EXAMIANS APP
Illumination A 1000 W bulb fitted with a reflector illuminates an area of 3 m x 3 m with an average illumination of 450 lux. If the bulb has and efficiency of 9 lumens / watt the efficiency of the reflector is 30 %. 70 %. 45 %. 20 %. 30 %. 70 %. 45 %. 20 %. ANSWER DOWNLOAD EXAMIANS APP
Illumination Total flux or lumens required in any lighting scheme depends inversely on reduction factor. utilization factor. reflection factor. None of these reduction factor. utilization factor. reflection factor. None of these ANSWER DOWNLOAD EXAMIANS APP
Illumination From a uniform light source having luminous intensity of 300 candelas, there exists a plane surface 15 m below. The value of illuminance at a point on the plane surface where the luminous flux rays are inclined at an angle of 30 to the surface is 17.32 lux. 58.45 Kilolux. 1.53 lux. 1.15 lux. 17.32 lux. 58.45 Kilolux. 1.53 lux. 1.15 lux. ANSWER DOWNLOAD EXAMIANS APP
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