An intensity of illumination of 4 flux is required at a distance of 5m from an electric lamp. What must be the luminous intensity of the lamp?

What is the SI unit of luminous intensity?

A lamp placed 70.0 cm from a screen on one side produces the same illumination as a standard 60 cd lamp placed 105 cm away on the other side of the screen. What is the luminous intensity of the first lamp ?

A lamp of luminous intensity 50 candela is placed at a distancde of 1 m from a wall What is the illuminacnce of the wall directly in front of lamp ? If another lamp of 100 cd is placed on the same line at a distance of 125 cm what is the illuminance now?

The intensity of sound from a point source is 1.0 xx 10^-8 Wm^-2 , at a distance of 5.0 m from the source. What will be the intensity at a distance of 25 m from the source ?

A frosted bulb which may be taken as an isotropic source, gives as illumination of 8lm//m^(2) at a distance of 5m. Calculate (i) its luminous intensity and (ii) the total luminous flux from the blub.

The illuminance of a screen situated at a distance of 5m from an electric bulb of power 500 watt is 120 "lumen"//m^(2) . Assuming normal incidence of light on screen calculate (i) the luminous intensity of the bulb and (ii) the luminous efficiency of the bulb.

The overall luminous efficient of a 100 W electric lamp is 25 lumen W^-1 . Assume that light is emitted by the lamp only in the forward half, and is uniformly distributed in al diredctionsin this half. Calculate the luminous flux falling on a plane object of area 1cm^2 placed at a distance of 50 cm from the lamp and perpendicular to the line joining the lamp and the object.

A source emits 31.4 W of radiant flux distributed uniformly in all directions. The luminous efficiency is 60 lumen watfi. What is the luminous intensity of the source ?