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. 17.5 lux. 18.5 lux. 12.5 lux. 13.5 lux. 17.5 lux. 18.5 lux. 12.5 lux. ANSWER DOWNLOAD EXAMIANS APP
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 2:1 2√2 : 1 1: 2√2 1:2 2:1 2√2 : 1 ANSWER DOWNLOAD EXAMIANS APP
Illumination What will be the total flux emitted by a source of 60 candle power? 60 lumens. 754.2 lumens. None of these. 0.001326 lumens. 60 lumens. 754.2 lumens. None of these. 0.001326 lumens. ANSWER DOWNLOAD EXAMIANS APP
Illumination The illumination of the surface varies directly with cosine of the angle between normal to surface and direction of the inclined light is given by None of these law of square inverse. both A and B. Lambert’s cosine law. None of these law of square inverse. both A and B. Lambert’s cosine law. ANSWER DOWNLOAD EXAMIANS APP
Illumination The range of visual spectrum is 480nm - 760nm. 480nm - 1000nm. 300nm - 760nm. 300nm - 1000nm. 480nm - 760nm. 480nm - 1000nm. 300nm - 760nm. 300nm - 1000nm. 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 45 %. 30 %. 70 %. 20 %. 45 %. 30 %. 70 %. 20 %. ANSWER DOWNLOAD EXAMIANS APP