AP EAMCET Engineering 21 Apr 2019 Shift 1 Paper

The ray diagram of refraction at a plane surface is shown below.
The value of ip is calculated as
ip‌‌=tan−1µ
‌‌=tan−1√2
‌‌=sin−1√‌

2

3

From Snell's law,
sin‌ip=µ‌sin‌r
sin‌r=‌

sin‌ip

µ

Substitute the givenvalues in the above equation.
sin‌r‌‌=‌

sin‌ip

µ

r‌‌=‌

1

√2

√‌

2

3

r‌‌=sin−1(‌

1

√3

)
The angle of the deviation is calculated as
δ=ip−r
=sin−1√‌

2

3

‌sin
The angle of reflection is,
θ‌‌=90∘−r
r‌‌=90∘−θ
sin−1‌

1

√3

‌‌=90∘−θ
‌

1

√3

‌‌=sin(90∘−θ)
Solve further,
cos‌θ‌‌=‌

1

√3

θ‌‌=cos−1‌

1

√3

The angle between incident and completely polarised light is calculated as
φ‌‌=ip+θ
‌‌=sin−1√‌

2

3

+cos−1(‌

1

√3

)
‌‌=2sin−1√‌

2

3