Question 394: Ray Optics

Question

Two thin lenses of focal lengths f1 and f2 are in contact and coaxial. The power of the combination is

Accepted Answer

$${1 \over f} = {1 \over {{f_1}}} + {1 \over {{f_2}}}$$
$$ 	herefore $$ Power P = $${{{f_1} + {f_2}} \over {{f_1}{f_2}}}$$

Answer

$${{{f_1} + {f_2}} \over 2}$$

Answer

$${{{f_1} + {f_2}} \over {{f_1}{f_2}}}$$

Answer

$$\sqrt {{{{f_1}} \over {{f_2}}}} $$

Answer

$$\sqrt {{{{f_2}} \over {{f_1}}}} $$

Ray Optics