Question

the radius of curvaturer of concave mirror is 40centimeter. find position of an object in front of mirror, so that its real image is 2 times the size of object.
plz answer with solution please

Answer 1

Answer: I have tried to answer. I hope this will help you..

If there is any doubt in mind you can tell..

Explanation:

Given that, radius of curvature ,R = -40 cm so focal length= -20 cm

        Let the height of the object be h cm

According to the question, height of image should be -2h cm

we know that,

                        m= - v/u = -2h/h

                                v/u  = 2

                                  v   = 2u

Mirror Formula

                1/f = 1/u +1/v

           - 1/20= 1/u +1/2u

            -1/20 =   2+1 /2u

             -1/20= 3/2u

              -2u = 60

                  u = -30 cm