When white light passes through a prism the colour which bends the least is :

Question

Accepted Answer

When white light passes through a prism, it undergoes dispersion, which causes the light to spread out into its constituent colors, forming a spectrum. This occurs because different colors of light have different wavelengths and refract, or bend, by different amounts when passing through the prism.

1. **Explanation for Option 2 (Red):** Red light bends the least when passing through a prism. This is because red light has the longest wavelength among the visible spectrum. The amount of bending, or refraction, that light undergoes is inversely related to its wavelength. Therefore, longer wavelengths, like that of red light, are refracted less than shorter wavelengths. As a result, red light appears at the top of the spectrum and bends the least compared to other colors.

2. **Explanation for why other options are incorrect:**

- **Option 1 (Indigo):** Indigo light has a shorter wavelength than red light. Shorter wavelengths are refracted more than longer wavelengths. Therefore, indigo light bends more than red light when passing through a prism, making this option incorrect.

- **Option 3 (Violet):** Violet light has the shortest wavelength in the visible spectrum, which means it bends the most when passing through a prism. This is the opposite of what is required for the color that bends the least, making this option incorrect.

- **Option 4 (Orange):** Orange light has a wavelength shorter than red but longer than yellow. While it bends less than colors like violet or indigo, it still bends more than red light. Therefore, orange is not the color that bends the least, making this option incorrect.

In conclusion, red light bends the least when white light passes through a prism due to its longer wavelength, which results in less refraction compared to other colors in the visible spectrum.