Question

A candle is placed 15 cm in front of a convex mirror when the convex mirror is placed with plane mirror the image more 7 cm further away from the mirror find the focal length of the convex mirror
One who tells me the correct answer I will mark you as brainlist and thankyou

Answer 1

Explanation:

as the image formed by convex mirror and by the plane mirror coincide the image distance formed by the convex mirror is 4

because , distance of image from plane mirror is 12 and the distance between plane mirror and convex mirror is 8 hence 12−8=4

let f be the focal lenght of the mirror ,

u=−20 ; v=+4

v

1

+

u

1

=

f

1

4

1

−

20

1

=

f

1

f=5

hence the focal lenght is 5cm