Question

a parallel beam of light incident on A lens seems to emanate from a point on the principal axis is at a distance of 25 CM then find the radius of curvature​

Answer 1

Answer:

髫聽笑尸林木 杰火 火烤 尸

Explanation:

尸 口 木木 杰 土日？ 已 ？

Answer 2

Radius of curvature= 50 cm

Explanation:

$R_1 = +ve ,R_2 = -ve$

$R_1 = R_2 = R$      (for equiconvex lens)

Since u = ∞  and f is +ve for converging lens

We know that,By Len's Formula,

$\frac{1}{f} = \frac{1}{v}- \frac{1}{u}$

$\frac{1}{f} = \frac{1}{v} - \frac{1}{\infty}$

$\frac{1}{f} = \frac{1}{25} -\frac{1}{\infty}$

$\frac{1}{f} = \frac{1}{25}-0$ 

$\frac{1}{f} =\frac{1}{25}$

f = 25 cm

We know that,

Radius of curvature =$2\times f$

                                 =$2\times 25$

                                 = 50 cm