The frequency of domestic power supply in India is

The correct answer is D. 50 Hz.

The frequency of domestic power supply in India is 50 Hz. This means that the voltage alternates between positive and negative 50 times per second. The frequency of the power supply is important because it affects the speed of motors and other electrical devices.

Option A is incorrect because the frequency of domestic power supply in India is not 200 Hz.

Option B is incorrect because the frequency of domestic power supply in India is not 100 Hz.

Option C is incorrect because the frequency of domestic power supply in India is not 60 Hz.