A) \[1.0\times {{10}^{8}}m/s\]
B) \[1.5\times {{10}^{8}}m/s\]
C) \[6\times {{10}^{8}}m/s\]
D) \[\sqrt{3}\times {{10}^{8}}m/s\]
Correct Answer: B
Solution :
Refractive index of medium \[\mu =\frac{1}{\sin C}\]. Where C is critical angle. Given, \[C={{30}^{o}}\] \[\therefore \] \[\mu =\frac{1}{\sin {{30}^{o}}}=\frac{1}{1/2}=2\] By Snell's law \[\mu =\frac{{{V}_{0}}}{{{V}_{m}}}\] Where \[{{V}_{0}}\] is the speed of light in vacuum and \[{{V}_{m}}\]the velocity in medium. \[\therefore \] \[{{V}_{m}}=\frac{3\times {{10}^{8}}}{2}=1.5\times {{10}^{8}}\,m/s.\] Note: As velocity of light in medium is smaller than in vacuum. Thus the medium is denser.
You need to login to perform this action.
You will be redirected in
3 sec
