AMU Engineering 2018 solved paper Solved Paper

Given, angle of prism =A
Refractive index, µ=cot‌

A

2

We know that, refractive index of prism is given by in the terms of angle of prism and minimum deviation
µ=

sin( A+δm 2 )

sin‌ A 2

⇒ cot‌

A

2

=

sin( A+δm 2 )

sin‌ A 2

cos‌ A 2

sin‌ A 2

.sin‌

A

2

=sin(

A+δm

2

)
cos‌

A

2

=sin(

A+δm

2

)
sin(

π

2

−

A

2

)=sin(

A+δm

2

)

π

2

−

A

2

=

A+δm

2

π−A=A+δm
π−2A=δm
⇒ δm=π−2A