Question

An object 5cm high forms virtual image of 1.25cm high, when placed in front of a convex mirror at a distance of 24cm. Calculate:(i) the position of the image (ii) the focal length of the convex mirror.
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Answer 1

Answer:

u=-10 cm for convex mirror, the object distance is -ve.

v=?

R= 30 cm

f =15 cm

ho= 5 cm

1/u+1/v=1/f

(-1/10)+(1/v)=(1/15)

1/v=1/15+1/10

1/v=(2+3)/30

1/v =5/30

v= 6 cm

size of the image

m= hi/ho =-v/u

=-6/10 =0.6

0.6=hi/5

hi=3 cm

The image is formed at a distance of 6 cm behind the mirror, virtual, upright and smaller than the object.

size of the image is 3 cm.

Thanks