The separation between the screen and a plane mirror is 2 r. An i… - Vidyadip

MCQ

The separation between the screen and a plane mirror is $2 r$. An isotropic point source of light is placed exactly midway between the mirror and the screen. Assume that mirror reflects $100 \%$ of incident light. Then the ratio of illuminances on the screen with and without the mirror is

A
$10: 1$
B
$2: 1$
✓
$10: 9$
D
$9: 1$

✓

Answer

Correct option: C.

$10: 9$

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