Question

Hø|ã !!

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At what distance from a concave mirror of focal length 10cm should an object 2cm long be placed in order to get an erect image 6cm tall ??

CLASS - X
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Answer 1

Hey mate ♥ here is ur answer

Answer 2

HeYa...

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Concave mirror , f is negative ,  f = -10 cm

   u = ?

 h = 2 cm 

 erect image  so  h' is positive,  h' = 6 cm

     so m = h'/h = 3

         as  m = -v/u = 3  => v = -3 u

   mirror equation  is  1/v + 1/u = 1/f

       1/(-3u) + 1/u = 1/(-10)

          2/(3u) = -1/10

            u = -20 /3 cm = -6.67 cm         and  v = -3 u = 20 cm

           v is positive,  so image is behind the mirror and is virtual.

  in concave mirror , an erect image is obtained when the object is between the pole and the focus. it is magnified and is virtual.  so  you can verify from values of u, v and f.