Question

Given below are two statements :
Statement I : When the white light passed through a prism, the red light bends lesser than yellow and violet.
Statement II : The refractive indices are different for different wavelengths in dispersive medium.
In the light of the above statements, choose the correct answer from the options given below :

• A. Both Statement I and Statement II are true.
• B. Statement I is true but Statement II is false.
• C. Both Statement I and Statement II are false.
• D. Statement I is false but Statement II is true.

Answer 1

The Correct Option is A

When white light passes through a prism, it undergoes dispersion due to varying refractive indices for different wavelengths. Among the colors in the visible spectrum, red light has the longest wavelength, while violet has the shortest. Since the refractive index is inversely proportional to the wavelength, red light bends the least, while violet light bends the most.

This phenomenon occurs because a higher refractive index results in greater bending, and shorter wavelengths correspond to higher refractive indices. Thus, red light deviates less compared to yellow and violet.

As \( \lambda_{\text{red}} > \lambda_{\text{yellow}} > \lambda_{\text{violet}} \), light rays with longer wavelengths bend less.

Therefore, both Statement I and Statement II are true.