Question

Physica
gi) Find angle of incidence if angle of
refraction is 20 degrees for a glass having refractive
index 1.5​

Answer 1

According to the laws of reflection angle of incidence is always equal to angle of reflection.

So angle of incidence = angle of reflection

=20°

Answer 2

Answer:

$\frac{sin \: \: i}{sin \: \: r} = n \\ \frac{sin \: \: i}{sin \: \: 20} = \frac{15}{10} \\ sin \: \: i \: = 30$

Angle of incidence is 30°