Question

4. A concave lens of focal length 30cm form an image 15 cm from the lens. How far is the object
placed from the lens? Draw the ray diagram.​

Answer 1

Answer:

Explanation:

Focal length (f ) = -15 cm

Distance of image (v) = -10 cm

1v–1u=1f

1/u = -(1/10) – (1/- 15)

1/u =1/15 – 1/10

1/u = -0.033

u = -30 cm

so thFocal length (f ) = -15 cm

Distance of image (v) = -10 cm

\(\frac{1}{v} – \frac{1}{u} = \frac{1}{f}\)

1/u = -(1/10) – (1/- 15)

1/u =1/15 – 1/10

1/u = -0.033

u = -30 cm

So, the object is placed 30 cm away from the concave lens.

Ray diagram:

e object is placed 30 cm away from the concave lens.