a concave mirror has focal length 15 cm and object distance 40cm find its image distance​

1 thought on “a concave mirror has focal length 15 cm and object distance 40cm find its image distance​”

1. Answer:

   36 cm

   Explanation:

   Initially:

   u

   i

   =−40cm f

   i

   =−15cm

   v

   i

   1

   +

   u

   i

   1

   =

   f

   1

   v

   i

   1

   +

   −40

   1

   =

   −15

   1

   ⇒v

   i

   =−24cm

   Finally: u

   f

   =−20cm f=−15cm

   v

   f

   1

   +

   u

   f

   1

   =

   f

   1

   ∴

   v

   f

   1

   +

   −20

   1

   =

   −15

   1

   ⇒v

   f

   =−60cm

   Thus image is shifted by 60−24=36cm

   (away from mirror)

   Option (4) is correct.

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