Question

Plzz say this answer​

Answer 1

Answer:

Here, size of object = O = + 10.0 mm = + 1.0 cm (as, 1 cm = 10 mm)

Size of Image size = I = 5.0 mm = 0.5 cm                                                             Image distance, v = − 30 cm   (as image is real)

Let, object distance = u

Focal length, f =?

Also, v=-30

∴u=-60

1/f = -1/30 + -1/60

1/f = -3/60

f = -20cm

Answer 2

Correct answer is Option b...✓✓✓