A ray of light suffers refraction through an equilateral prism. The deviation produced by the prism does not depend on the:

1. angle of incidence
2. colour of light
3. material of prism
4. size of prism

In the figure given ahead the correct statement is:

1. ABED and ABC are the refracting surfaces.
2. line AD is the refracting edge
3. angle a is the angle of deviation
4. AB is the base of the prism.

The angle of prism A is given as:

1. r₁ - r₂
2. i₁ + i₂
3. r₁ + r₂
4. r₁ / r₂

The angle of deviation becomes minimum when:

1. i₁ = r₁
2. i₁ = r₂
3. i₁ = i₂
4. r₂ = i₂