Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  • Light is incident from a medium into air at two possible angles of incidence (a) 20o and (b) 40o. In the medium light travels 3.0 cm in 0.2 ns. The ray will :<di

Light is incident from a medium into air at two possible angles of incidence (a) 20o and (b) 40o. In the medium light travels 3.0 cm in 0.2 ns. The ray will :

Option: 1

Suffer total internal reflection in both cases (a) and (b)


Option: 2

Suffer total internal reflection in case (b) only.


Option: 3

have partial reflection and partial transmission in case (b) 


Option: 4

have 100% transmission in case (a)


Answers (1)

best_answer

Velocity of light in the medium = 

\frac{3 \times 10^{-2}}{0.2 \times 10^{-9}}=1 \cdot 5 \times 10^{8} m / s

 

Since, 

\mu=\frac{v_{a}}{v_{m}}=\frac{3 \times 10^{8}}{1 \cdot 5 \times 10^{8}}=2

So, critical angle= \sin ^{-1} \frac{1}{2}=30^{\circ}

Since in the second case the angle of incidence is greater than critical angle. SO total internal reflection occur in case (2)

Posted by

vinayak

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

73 or 99 percentile? JEE Main result questioned, J-K candidate says, ‘Don’t create hype’
anam-khan

JEE Main 2025: 11 from Kota coaching centres among 24 students with 100 percentile
anam-khan

Low JEE Main rank? Explore alternative paths for engineering admission

Latest Question