Question

A converging lens has a focal length 15cm. An object is placed at 60cm from the lens. Determine the image.

Answer 1

It is a converging lens that is convex lens

Focal length , f = 15 cm
Object distance , u = - 60 cm
Image distance, v = v

Lens formula
1/v - 1/u = 1/f

1/v - (1/-60) = 1/15
1/v +1/60 = 1/15
1/v = 1/15+1/60
1/v = ( 4 +1)/60
1/v = 5/60
V = 12 cm

Answer 2

Answer:

Therefore, the distance of image from the pole is 20cm.

Explanation:

Given that, it is a converging/convex lens,

$\therefore$ Focal length, $f = 15 cm$,

Object distance, $u = - 60 cm$

and Image distance, $v = ?$

Using the Lens formula,

$\frac{1}{v} -\frac{1}{u} =\frac{1}{f}$

Putting in the given values,

$\implies \frac{1}{v} -\frac{1}{-60} =\frac{1}{15}$

$\implies \frac{1}{v} =\frac{1}{15}-\frac{1}{60}$

$\implies \frac{1}{v} =\frac{4-1}{60}$

$\implies \frac{1}{v} =\frac{3}{60}$

$\implies v=20cm$

Therefore, the distance of the image from the pole is 20cm.

#SPJ2