Illumination Objective Questions

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

Luminous efficiency of a fluorescence lamp is

Solid angle is expressed in terms of

Total flux or lumens required in any lighting scheme depends inversely on

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

The unit of solid angle is

What will be the total flux emitted by a source of 60 candle power?

From a uniform light source of 300 c.p. there exists a plane surface 15 m below the value of illumination on the plane surface when the luminous flux rays are inclined at an angle of 30 to the surface is

Candela is the unit of

A solid angle can be expressed in terms of

Which of the following statement is correct?

The solid angle subtended by an area of 2400 cm² on the surface of a sphere of diameter 1.2 m is

ψ Wave length for red colour is

Carbon arc lamps are commonly used in

Unit of luminous flux is

Illumination can be expressed in

Radiant efficiency of the luminous source depends on

___________________________ factor is defined as the ratio of the illumination when everything is clean to illumination under normal working conditions.

Candela is the unit of which?

In illumination technology total lumens emitted by source / total lumens available after waste of light is equal to