Question

An object is placed at infinity in front of a
concave mirror of radius off curvature 40
cm. The image will be formed in front of the
mirror a distance of:
0 20 cm
0 30 cm
040cm
O 50 cm​

Answer 1

Answer:

20 cm

Explanation:

Since the object is at infinity the image is formed at the focus .

we can confirm that by the mirror formula

1/f = 1/u +1/v

here u= infinity f=R/2 =40/2 = 20

1/20 = 1/infinity +1/v

since 1/infinity is zero

1/20 = 1/V

v= 20 cm