A-lens-is-required-to-have-a-power-of-2-5-dioptres-in-air-the-convex-front-surface-has-a-radius-of-curvature-of-30cm-calculate-the-radius-of-curvature-of-the-rear-surface-

Question Number 134323 by aurpeyz last updated on 02/Mar/21

A l e n s i s r e q u i r e d t o h a v e a p o w e r o f

- 2.5 d i o p t r e s i n a i r . t h e c o n v e x

f r o n t s u r f a c e h a s a r a d i u s o f c u r v a t u r e

o f 30 c m . c a l c u l a t e t h e r a d i u s o f c u r v a t u r e

o f t h e r e a r s u r f a c e

Answered by ajfour last updated on 02/Mar/21

\frac{1}{f} = (μ - 1) (\frac{1}{R_{1}} - \frac{1}{R_{2}})

- \frac{5}{2} = \frac{1}{2} (\frac{100}{30} - \frac{100}{R_{2}})

\Rightarrow \frac{100}{R_{2}} = 5 + \frac{100}{30} = \frac{25}{3}

R_{2} = 12 c m

Commented by aurpeyz last updated on 02/Mar/21

a p p r e c i a t e d t h a n k s

Commented by aurpeyz last updated on 02/Mar/21

w h a t i s t h e v a l u e o f μ ?

Commented by ajfour last updated on 02/Mar/21

r e f r a c t i v e i n d e x o f l e n s (g l a s s)

w i t h r e s p e c t t o t h a t o f t h e

m e d i u m s u r r o u n d i n g t h e l e n s

(h e r e a i r) .

Commented by ajfour last updated on 02/Mar/21

d i f f e r e n t g l a s s e s m a y h a v e

d i f f e r e n t v a l u e s o f r e f r a c t i v e

i n d e x, i f n o t g i v e n i n q u w s t i o n

(s u c h a s y o u r s) w e t a k e i t t o b e

μ_{g l a s s} = 1.5, μ_{a i r} = 1

Commented by aurpeyz last updated on 02/Mar/21

y o u c h a n g e d 1 t o 100 i n l i n e 2

Commented by ajfour last updated on 02/Mar/21

P o w e r i n d i o p t r e s i s o b t a i n e d

f r o m P = \frac{1}{f} o n l y w h e n

f i s i n m e t r e s . S o i c o n v e r t e d

t o o k R_{1} = \frac{30}{100} m

Commented by aurpeyz last updated on 02/Mar/21

t h a n k s s o m u c h . i a p p r e c i a t e a l o t

Commented by aurpeyz last updated on 02/Mar/21

t h a n k s s o m u c h . i a p p r e c i a t e a l o t

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