Question

When white light is incident on a prism, which of the following ray will experience lesser deviation?

• A. Black
• B. Green
• C. Violet
• D. Red

Answer 1

Answer: (D)

Red

Red suffers least deviation because it has largest wavelength among VIBGYOR.

$c=\lambda \times \nu$

So its speed is largest, that means

$\mu =\frac{c}{v}$

Refractive index will be less.

as, $\delta =(\mu -1)\times A$