A ray of light passes through an equilateral glass prism in such a manner that the angle of incidence is equal to the angle of emergence and each of these angles is equal to $(\frac{3}{4})th$ of the angle of prism. The angle of deviation is:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 30°
The angle of deviation is,
$D=i+e-A$
$=i+e-A$ $[i=e=\frac{3}{4}×60=45]$
$=2×45-60$
$=30°$