First slide

Coherent sources and their importance in interference

Question

The length of plane mirror is 1cm. The wavelength of source is $5000 A^{0}$ . The number of maxima formed on the large screen are (P is central point on screen)

Moderate

A

19,999
B

20,000
C

20,001
D

39,998

Solution

$A n i m a g e S' w i l l f o r m a t 5 m m b e h i n d t h e m i r r o r . H e n c e, P a t h d i f f e r e n c e a t P = ∆ x = S' P - S P = 10 m m A l s o, ∆ x = n λ [C o n d i t i o n f o r m i n i m a, a s m i r r o r i n t r o d u c e s p h a s e d i f f e r e n c e o f π] \Rightarrow n = \frac{∆ x}{λ} = \frac{10 \times 10^{- 3}}{5 \times 10^{- 7}} = 20, 000^{t h} m i n i m a A t i n f i n i t y, ∆ x = 0 m e a n s m i n i m a H e n c e, b e t w e e n l o w e r I n f i n i t y a n d p o i n t P, 19, 999 m a x i m a e x i s t s . N o i n t e r f e r e n c e o c c u r a b o v e p o i n t P .$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App