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An achromatic doublet is formed by combi...

An achromatic doublet is formed by combining two lenses.if the focal length of the lenses and their dispersive powers are `f,f^(')`and `omega, omega^(')` respectively then

A

`omega=omega_(0),omega'=2omega_(0),f'=2f`

B

`omega=omega_(0),omega'=2omega_(0),f'=-2f`

C

`omega=omega_(0),omega'=2omega_(0),f'=f/2`

D

`omega=omega_(0),omega'=2omega_(0),f'=-f/2`

Text Solution

Verified by Experts

The correct Answer is:
B
`omega/f+(omega.)/(f.)=0`
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