Question

A lens forms a virtual image of an object at a distance of 40 cm

from the lens. The focal length of the lens is 10 cm.

(i) Name the type of this spherical lens.

(ii) Calculate the distance between the object and the lens.


pls answer asap
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Answer 1

Answer:

Given that,

The lens forms virtual image

Explanation:

1)The type of lens is concave lens

2) The image distance(v) =40cm

The focal length of lens =10cm

Through the lens formula =1/f=1/v-1/u

Here,f=10cm,v=40cm,u=?

By applying sign conventions

For concave lens,f=-ve,u=-ve,v= -ve

l/-f=1/-v-1/-u

l/-10=1/-40+1/u

1/-10+1/40=1/u

-8+2/80=1/u

-6/80=1/u

-80/6=u

-12.2=u

The distance between the object and the lens =12.2cm

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