Q. 35.0( 1 Vote )

Consider a ray of A.

B.

C.

D.

Answer :


Time taken by purple ray to travel through a slab of reflective index n is given



The speed of light will decrease due to resistance given by medium; therefore it is given by c/n. And from snell’s law we already know a relation between n, r and θ. This is given by



But the option given in question requires a relation between θ and n, therefore we need to convert sin(r) into a suitable form. This could be done using simple trigonometric identity.



And we know sin �2r can be converted into sin2θ form using snell’s law relation.



Now for time T, phase difference is given 2π, therefore for ∆time, it will be given by


And c*T=λ. Therefore,





After re-arranging terms, we get



Now important thing to note is that when a wave from rarer medium get reflected by denser medium it suffers a phase difference by π. But when a wave from denser medium gets reflected by rarer medium no such phase difference is observed. Therefore net phase difference is given by



Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses
RELATED QUESTIONS :

<span lang="EN-USPhysics - Exemplar

Define the term wPhysics - Board Papers

(i) State and expPhysics - Exemplar

<span lang="EN-USPhysics - Exemplar

Consider a point Physics - Exemplar

Consider a ray ofPhysics - Exemplar