A glass prism has a refractive angle of `90^(@)` and a refractive index of 1.5. A ray is incident at an angle of `30^(@)`. The ray emerges from an adjacent face at an angle of

Options

A. `60^(@)`
B. `30^(@)`
C. `45^(@)`
D. the ray does not emerge

Answer

D

Explanation

(d) Critical angle, `theta_(C)=sin^(-1)(1/1.5)=41.8^(@)`
Incident angle, `i_(1)=30^(@)`
`sinr_(1)=(sini_(1))/(mu)=(sin(30^(@)))/(1.5)`
`r_(1)=19.5^(@)`
or Angle of emergence, `r_(2)=A-r_(1)=90-19.5=70.5^(@)`
Since, `r_(2)gttheta_(C)`
`therefore` The ray will not emerge from the prism.