When light of wavelength λ falls on a thin film of thick- ness t and refractive index n, the essential conditions for the production of constructive interference fringes by the rays A and B is: (m = 1,2,3,...)

Question

When light of wavelength λ falls on a thin film of thick- ness t and refractive index n, the essential conditions for the production of constructive interference fringes by the rays A and B is: (m = 1,2,3,...) (A)  2nt cos r=( m-(1/2) )λ  (B)  2nt cos r=mλ  (C)  nt cos r=( m-(1/2) )λ  (D)  nt cos r=mλ

Tardigrade Admin · Accepted Answer

Correct answer is (a) 2nt cos r=( m-(1/2) )λ

Q. When light of wavelength $λ$ falls on a thin film of thick- ness t and refractive index n, the essential conditions for the production of constructive interference fringes by the rays A and B is: (m = 1,2,3,...)

$2 n t cos r = (m - \frac{1}{2}) λ$

$2 n t cos r = mλ$

$n t cos r = (m - \frac{1}{2}) λ$

$n t cos r = mλ$

Correct answer is (a) $2 n t cos r = (m - \frac{1}{2}) λ$

Q. When light of wavelength λ falls on a thin film of thick- ness t and refractive index n, the essential conditions for the production of constructive interference fringes by the rays A and B is: (m = 1,2,3,...)

2ntcosr=(m−21​)λ

2ntcosr=mλ

ntcosr=(m−21​)λ

ntcosr=mλ