Question 402: Ray Optics

Question

A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will

Accepted Answer

$${1 \over f} = \left( {\mu  - 1} ight)\left( {{1 \over {{R_1}}} - {1 \over {{R_2}}}} ight)$$
Where $$\mu  = {{{\mu _{convex\,lens}}} \over {{\mu _{liquid}}}}$$ = 1
$$ 	herefore $$ $${1 \over f} = \left( {1 - 1} ight)\left( {{1 \over {{R_1}}} - {1 \over {{R_2}}}} ight) = 0$$
$$ \Rightarrow $$ f = $$\infty $$

Answer

become zero

Answer

become infinite

Answer

become small, but non-zero

Answer

remain unchanged

Ray Optics

A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will

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