A 100 candela lamp emits light uniformly in all directions and is suspended 2m above the center of a working table which is 3m square. Calculate the illumination at each corner of the table.

At what distance from a wall will 40 Cd lamp provide the same illumination as 80 Cd lamp located at 4 m from the wall?

An office, 17 m x 8m wide is lighted by 8 lamps and each lamp has a luminous intensity of 200 Cd. Allowing an absorption loss of 4,000 Im for the reflectors, walls, and ceiling. Calculate the average illumination on the working plane.

A light source has an illumination of 100 footcandles (fc), what is the illumination in lux?

For indoor lawn tennis, what is the recommended level of illumination for tournaments in foot-candles (fc)?

What is the total flux emitted by a lamp having an intensity of 50 candelas?

A room measuring 16m by 8m is to be illuminated by 8 lamps with an average illumination of 72 lm/sq.m at floor level. If 40% of the total light emitted is absorb by the walls and ceiling, calculate the mean spherical candle power required for each lamp.

A certain light source produces an illumination of 800 lux on surfaces. Find the illumination of 800 lux on surfaces. Find the illumination on that surfaces if the distance to the light is doubled.

A road is illuminated by two 500 candela lamps placed 6.1 meters above the center line of the road and 18.3 meters apart. Find the illumination produced on the surface of the road at a point on the center line midway between lamps.

What is the burning hours that should be used in the design consideration of incandescent bulb?

How far from a 150 Cd light source would a picture have to be placed so as to receive the same illumination as when it is placed 12m from an 85 Cd light source?

A room with dimensions of 72 ft x 36 ft x 13 ft requires 50 footcandles, maintenance factor of 0.7 coefficients of utilization of 0.46 and RI of 4. Calculate the required lumens output of the lamps.

A light source located 2.75 m from a surface produces an illumination of 528 lux on the surface. Find the illumination if the distance is changed to 1.55 m.

A floodlight emitting 25000 candelas in the center of its beam is aimed at 60 degrees to a point on the ground 20 meters away. The illumination of the point is,

A uniform light source gives 2500 lm and is suspended 3.2 m above the center of a horizontal floor, 4m square. Find the illumination in lux at a point on the floor directly below the light source.

A uniform light source gives 2500 lm and is suspended 3.2 m above the center of a horizontal floor, 4m square. Find the illumination in lux at each corner of the horizontal floor.

A 150 cd lamp at a distance of 12.37 m give sufficient illumination on a certain working plane. How far in meters a 250 cd lamp be placed to have the same illumination on the working plane as before?

A 540 cd lamp is 3m directly above a point A on the horizontal floor. If a plane mirror which reflects 75% of the light reaching it is placed horizontally 20 cm above the lamp, what will be the illumination at point A in lux?

A room, 8m by 12m is lighted by 15 lamps to a fairly uniform illumination of 100 lux. Calculate the coefficient of utilization given that each lamp emitted 1600 lm.

A room with dimension of 72 ft by 36 ft by 13 ft requires an illumination of 60 foot-candles. MF = 0.7 and CU = 0.6. Calculate the required lumens output of the lamps.

At what distance from a wall will 4 cd lamp provide the same illumination as a 8 cd lamp located 4m from the wall?

An area of 3 m^2 is to be illuminated by a light source at a level of 550 lux. Find the luminous flux emitted by the light source in lm.

A small wind generator is designed to generate 50kW of power at a wind velocity of 25 mph. What is the approximate blade diameter?

At what distance from a wall will 4 cd lamp provide the same illumination as a 8 cd lamp located 4m from the wall?

Determine the average illumination of a room measuring 9.15 m by 12.2 m illuminated by a dozen 150 watt lamps. The luminous efficiency of each lamp is 14 lm/watt, MF = 1 and CU = 0.35.

A factory space, 33m by 13m is to be illuminated by an average of 72 lux by 200 watt lamps. MF = 0.71 and CU = 0.4. The lumen output of 200 watt lamp is 2730 lm. Find the number of lamps required.

An unshaded lamp is 6m above the table. It is lowered down by 2m. By how much is the illumination on the table?

How many lumens passed through an area of 0.8 m^2 on a sphere of radius 3m if a 650 cd isotropic source is at the center?

A lamp produces an illumination of 10 lux at a point 10m directly below it. What is its luminous intensity?

Calculate the mean spherical candle power of a lamp emitting a flux of 1500 lumens.