An electric bulb is hanging over a table at a height of 1 m above it. The illuminance on the table directly below the
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) 10 lux
(b) 14 lux
(c) 20 lux
(d) 28 lux.
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