Question

(a) A security mirror used in a big showroom has radius of curvature 5 m. If a customer is standing at a distance of 20 m from the cash counter, find the position, nature and size of the image formed in the security mirror.

B) Neha visited a dentist in his clinic. She observed that the dentist was holding an instrument fitted with a mirror. State the nature of this mirror and reason for its use in the instrument used by dentist

Answer 1

Answer:

A) V=20/9 = 2.2m

Nature-virtual and erect

Size- Smaller than object size.

B) Concave mirror

Explanation:

A) mirror must be convex as would like to get erect image even at far distance for mirror so it can only be done by the convex mirror.

Given:-

R= 5m

f= 5/2m

u= -20m

So by using mirror formula,

1/f = 1/v + 1/u

1/v = 1/f - 1/u

1/v = 2/5 - (-1/20)

1/v = 20/9 = 2.2m

B) concave mirror because

I) it produces real image.

II) it produces enlarged image.

Hope you understood.

Thank you.