When an object of height 1 cm is kept at a distance 4 cm from a concave mirror ,its erect image of height 1.5 cm is formed at a distance 6 cm behind the mirror .Find the focal length of mirror?

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Solution

formula 1/u + 1/v = 1/f

As per cartesian sign convention, u = - 4 and v = 6 and f = -ve

Plug -1/4 + 1/6 = -1/f

Or - 1/12 = -1/f

==> f = 12 cm

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When an object of height 1 cm is kept at a distance 4 cm from a concave mirror ,its erect image of height 1.5 cm is formed at a distance 6 cm behind the mirror .Find the focal length of mirror?

formula 1/u + 1/v = 1/f As per cartesian sign convention, u = - 4 and v = 6 and f = -ve Plug -1/4 + 1/6 = -1/f Or - 1/12 = -1/f ==> f = 12 cm

formula 1/u + 1/v = 1/f

As per cartesian sign convention, u = - 4 and v = 6 and f = -ve

Plug -1/4 + 1/6 = -1/f

Or - 1/12 = -1/f

==> f = 12 cm