Question

The frequency of AC mains in India is
(A) $110C{s^{ - 1}}$
(B) $50C{s^{ - 1}}$
(C) $60C{s^{ - 1}}$
(D) $120C{s^{ - 1}}$

Answer 1

Hint: Frequency of AC or alternating current is defined as the number of cycles current completes per second. The frequency of AC which reaches our home is called the main frequency.

 Complete step by step answer:
We know that the frequency is the measure of the total number of sinusoidal cycles completed in one second. Hence we can say the current changes its direction twice during a complete cycle. It means that in the second alternating current changes its direction twice the no of frequency.
European countries use 50Hz as the AC mains. India also uses the 50Hz as their AC main frequency.
We already know that, alternating current changes its direction twice the times of frequency
So, this is the actual AC that is reaching us is equal to the twice the time of frequency AC main which is 100MHz and we use it for all our electrical needs.
India and most European countries use the electricity which has the frequency of AC mains as 50Hz.
The frequency Of A.C. mains in India is equal to \[{\text{50C/s}}\]
Hence, option (B) is the correct option.

Additional information:
The frequency of AC main in the USA, Australia, Canada, and China are 60Hz, 50Hz, 60Hz, and 50 Hz respectively.
Frequency is also known as temporal frequency and is different from angular or spatial frequency.
Angular frequency is the angular displacement per unit time or the rate of change of the phase of a sinusoidal waveform, or as the rate of change of the argument of the sine function. It means the angular frequency is possessed only by rotating objects. It is represented by ω.
Frequency is also defined as the reciprocal of the period. It is the duration of time taken by one cycle in a repeating event.
Frequency is used in many ways. It is used to measure the rate of oscillatory and vibratory phenomena, for example, mechanical vibrations, radio waves, audio signals (sound), and light.

Note:
1. In our domestic circuits, the frequency of Ac hertz is 50Hz; which means it changes its direction after every 1/100s.
2. The average value of an AC for one complete cycle is zero.
3. In a purely inductive circuit, the current decreases with an increase in frequency.
4. In a purely capacitive circuit, the current increases with an increase in frequency.