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Question
If the critical angle of a medium is sin-1(3/5), find the polarising angle.
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Solution
Given :
The critical angle is given as
sinθc = 1/n
`therefore theta_c=sin^-1(1/n)` ...(1)
It is given that
`theta_c=sin^-1(3/5)`
`therefore sin^-1(1/n)=sin^-1(3/5)` ...........form (1)
`therefore 1/n=3/5`
`therefore n=5/3`
Now, the polarising angle is given as
`theta_p=tan^-1 n`
`theta_p=tan^(-1)(5/3)`
`theta_p=tan^(-1)(1.667)`
`theta_p=59^@2'`
the polarising angle is `59^@2'`
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