Question

The velocity of light in vacuum can be changed by changing _____________?

• A. Frequency
• B. Wavelength
• C. Amplitude
• D. None of these

Answer 1

The correct option is D

None of these

Explanation

Option (D) None of these

1. The speed of light cannot be changed in a vacuum because it is constant in a vacuum$(c=3\times {10}^{8}m/s)$.
2. When light travels through any medium other than a vacuum, its speed is lower than in the vacuum.
3. When traveling through some media, it can be that the speed of light will be different for different wavelengths.
4. In a vacuum, the speed of light is constant and independent of the wave's properties such as frequency.
5. The ratio of the speed of light to the speed of light in a particular medium is known as the refractive index.
6. The electromagnetic wave frequency alone determines the wavelength in a vacuum, and the wavelength is inversely proportional to the frequency.
7. Hence speed of light depends on the medium and if the medium is the same (vacuum), it will remain constant.

Hence option D is the correct option