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what is the position and nature of im...

what is the position and nature of image formed by lens combination shown in figure ? `(f_(1),f_(2) ` are focal lengths)

A

`(20)/(3)cm` from point B at right, real

B

40 cm from point B at right, real

C

70 cm from point B at left, virtual

D

70 cm point B at right, real

Text Solution

Verified by Experts

The correct Answer is:
D
`(1)/(V)+(1)/(20)=(1)/(5)`.
`(1)/(V)=(1)/()-(1)/(20)=(4-1)/(20)`
`V_1=20//3`
Distance of first image from B
`20//3-2 =(14)/(3)cm`
For second lens
`(1)/(V)-(3)/(14)=(1-1)/(5)=(15-14)/(70)=(1)/(70)`
Real image 70 cm rightof B .
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