Question

At what voltage and frequency is the a.c. supplied to our houses?
A. $240\,V,\,50\,Hz$
B. $220\,V,\,100\,Hz$
C. $220\,V,\,50\,Hz$
D. $260\,V,\,50\,Hz$

Answer 1

Hint:Alternating current is supplied to our houses as it is easier to distribute over large distances with very low losses and a bit safer. The voltage in our homes is in the range of $220\,V - 240\,V$ . The voltage and frequency used in most of Asia, South America and Australia is of $220\,V - 230\,V,\,50\,Hz$

Complete answer:
 There are basically two types of currents; alternating current and direct current. AC is more efficient and has low power loss. While in DC there is more power loss. Alternating current is known as alternating because it reverses its direction after it travels some distance.

The electricity line in Indian houses comprises three wires; live wire, neutral wire, and the Earth wire. The live wire has a potential of $220\,V$ and the neutral wire has zero potential. As a result, the potential difference is $220\,V$ .

In India, the AC supplied is of $220\,V$ . The rate at which the current reverses direction is known as frequency. The standard frequency in India is $50\,Hz$ .

Therefore, option C is the correct answer.

Note: Remember that the voltage for houses in India is $220\,V$ and the frequency is of $50\,Hz$.In other countries, USA the electric power line has voltage of $110\,V - 120\,V$. The fans, tube lights in Indian trains are supplied with $110\,V$ DC and their operating voltage is $90\,V - 140\,V$ . These protect against theft of electric appliances as they won’t be useful at homes.Dynamos and transformers are used to maintain the potential drops.