A lamp is hanging at a height of `4 m` above a table. The lamp is lowered by `1 m` . The percentage increase in illuminace will be

A lamp hanging 4 metres above the table is lowered by 1 metre. Illumination on the table

A man of height 1.2 m walks away from a lamp hanging at a height of 4.0 m above ground level. If the man walks with a speed of 2.8 m//s , determine the speed of the tip of man's shadow.

An electric bulb is hanging over a table at a height of 1 m above it. The illuminance on the table directly below the bulb is 40 lux. The illuminance at a point on the table 1 m away from the first point will be about

An electric bulb is hanging over a table at a height of 1 m above it. The illuminance on the table directly below the bulb is 40 lux. The illuminance at a point on the table 1 m away from the first point will be about

An electric bulb is hanging over a table at a height of 1 m above it. The illuminance on the table directly below the bulb is 40 lux. The illuminance at a point on the table 1 m away from the first point will be about

A lamp of 120 candela hangs at a height of 4 m excathy above the centre of a circular table of diameter of 6.m Caluclate the illuminance at the centre and at the edge of the table.

Statement I : If the current of a lamp increases by 20 % , the percentage increases in the illlumination of the lamp is 40% . Statement II : Illumination of the lamp is directly proportional to the square of the current through the lamp.