Question

17.A 2.0 cm long pin is placed perpendicular to the principal axis of a convex lens of focal length 12cm. the distance of the pin from the lens is 15cm. find the size of the image.

(4 Points)

2cm

4cm

6cm

8cm​

Answer 1

Answer:

for the convex lens Focal length is positive .....

Given that - F = + 12 cm

U = - 15 cm

size of object (O) = 2.0 cm

V = ?

size of image ( I ) = ?

by lens formula ,

1 / F = 1 / V + 1 / U

1 / V = 1 / F - 1 / U

1 / V = 1 / 12 - (1 /-15)

1 / V = 1 / 12 + 1 / 15

1 / V = ( 5 + 4 ) / 60

1 / V = 9 / 60

V = 60 / 9 = 6.66 cm

M = V / U = I / O

I / O = V / U

I / 2 = 6.66 / - 15

I = - 0.44 x 2 = - 0.88 cm

size of image is 0.88 cm....

thnks for asking.....