Question

The frequency of AC mains in India is
\[\begin{align}
  & A)100Hz \\
 & B)50Hz \\
 & C)\dfrac{1}{100}Hz \\
 & D)\dfrac{1}{50}Hz \\
\end{align}\]

Answer 1

Hint: The definition of frequency of an AC or alternating current is given as it is the number of cycles that the current completes in one second. Mains frequency is the frequency of the AC current that reaches our homes and which we use for our daily purposes. The AC mains frequency is determined by the country itself.

Complete step by step answer:
We know that frequency of AC or alternating current is the measure of how many total cycles that the sinusoidal variation of the current that completes in one second. In one cycle, the current changes direction twice, that means in one second, the alternating current will change its direction two times of its frequency.
If we take the mains frequency of European countries, they use \[50Hz\]. In India, we also follow the same frequency as the AC mains frequency. Hence, the current that we use for household use changes its direction twice the frequency, that is \[(50Hz\times 2=100)\] 100 times in a second.
So, we can conclude that the frequency of AC mains in India is \[50Hz\]. So, the right answer given in the options is option b.

Hence, the correct option is B.

Note:
If we notice the difference of plug points in the USA and India. This is because the AC mains frequency in the USA is \[60Hz\] and India is \[50Hz\]. We must know that the impedance of a circuit largely depends on frequency of AC mains. So, there must be no variation in the mains frequency. All the electrical products made for Indian market are configured as they could work optimally at \[50Hz\].