Question

When a ray of white light is incident obliquely on the first surface of a prism, then ______.

Options

• Red colour is deviated most.

• Green colour is deviated most.

• Yellow colour is deviated most.

• Violet colour is deviated most.

Answer 1

When a ray of white light is incident obliquely on the first surface of a prism, then violet colour is deviated most.

Explanation:

Shorter wave lengths (like violet) deviate more in a prism due to increased refraction, whereas longer wavelengths (like red) deviate least. The deviation of light in a prism is dependent on its wavelength.