JEE MAIN - Physics (2003 - No. 22)
To get three images of a single object, one should have two plane mirrors at an angle of
$${60^ \circ }$$
$${90^ \circ }$$
$${120^ \circ }$$
$${30^ \circ }$$
توضیح
When $$\theta = {90^ \circ }$$ then $${{360} \over \theta } = {{360} \over {90}} = 4$$
is an even number. The number of images formed is given by
$$n = {{360} \over \theta } - 1 = {{360} \over {90}} - 1 = 4 - 1 = 3$$
is an even number. The number of images formed is given by
$$n = {{360} \over \theta } - 1 = {{360} \over {90}} - 1 = 4 - 1 = 3$$