Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping

Good afternoon sir. Answer is 3rd option. Explain it sir.

Good afternoon sir.
Answer is 3rd option.
Explain it sir.

Question Image
Grade:

1 Answers

Arun
25763 Points
3 years ago
let the refractive index be RI 
angle of from air to glass slab incidence = 45 degrees. 
let R1 be the angle of refraction 
sin(45 deg)/sin(R1) = Ri 
sin(R1) = sin(45 deg)/(Ri) 
angle of incidence of the ray on the vertical face of the slab as it travels through it is (90 degrees - R1) 
sin(90)/sin(90 deg -R1) = Ri (here angle of refraction should be 90 degrees because we need total internal reflection) 
1/cos(R1) = Ri 
cos(R1) = 1/Ri 

using sin square theta + cos Square theta = 1, we have square(sin(45 deg)/Ri) + square(1/Ri) = 1 
square(1/(sqrt(2)*Ri)) + square(1/Ri) = 1 
1/(2*square(Ri) + 1/square(Ri) = 1 
=3/(2*square(Ri) ) = 1 
square(Ri) = 3/2 Hence Ri = sqrt(3/2) 

 

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

ASK QUESTION

Get your questions answered by the expert for free