A) \[1.5\times {{10}^{8}}m/s\]
B) \[3\times {{10}^{8}}m/s\]
C) \[4.5\times {{10}^{8}}m/s\]
D) none of these
Correct Answer: A
Solution :
The critical angle is the angle of incidence in the denser medium for which the angle of refraction in the rarer medium is\[{{90}^{o}}\]. \[\therefore \] \[\mu =\frac{\sin {{90}^{o}}}{\sin C}=\frac{1}{\sin C}\] ?.. (i) Also, \[\mu =\frac{{{v}_{0}}}{v}\] ...(ii) where\[{{v}_{0}}\]is speed of light in vacuum and v is speed in medium. From Eqs. (i) and (ii), we get \[v={{v}_{0}}\,\sin C=3\times {{10}^{8}}\times \frac{1}{2}\] \[=1.5\times {{10}^{8}}m/s\]You need to login to perform this action.
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