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A concave mirror and convex lens (both o...

A concave mirror and convex lens (both of refractive index 1.5) have focal length 3 cm in air. When they are placed in water ofrefractive index `4/3`, then their new focal lengths will be ......

A

`f_("lens")`=12 cm ,`f_("mirror")`=3 cm

B

`f_("lens")`=3 cm ,`f_("mirror")`=12 cm

C

`f_("lens")`=3 cm ,`f_("mirror")`=3 cm

D

`f_("lens")`=12 cm ,`f_("mirror")`=12 cm

Text Solution

Verified by Experts

The correct Answer is:
A, B, C
New focal length of convex lens = `4 xx 3 = 12` cm When concave mirror is kept in water then its focal length remains unchanged hence new focal length = 3 cm.
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