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State the disadvantage of direct current.
A Direct Current (DC) is a constant value of current which does not change with the time. It flows in one direction only, that is from positive to negative. The current here does not change its direction at all. It is always from positive terminal to negative terminal.
Disadvantage of Direct current:
Generally, the electricity is produced in a power plant which is far away from the main city. To supply the electricity to houses we have to transport it into the city. Electricity is transported through wire. Now in the previous chapter you have studied about Joule's law of heating. If we transport electricity in form of Direct Current through wires, a major portion of the electricity is already lost and wasted in form of heat which will cause nothing but loss. This is the major disadvantage of the Direct Current. It is prevented by transporting Alternating Current instead of direct current. Which does not really have heating problem.
Mr. Sharma used to park his car in the basement of his house. One day in the morning he noticed that his basement is full of knee-deep water and its walls were wet because of the hours-long rain at night. When he entered the basement, he experienced a major shock. His father seeing him from outside, rushed to the main switch and switched it off and thus saved his life.
(a) Why Mr. Sharma experienced the shock?
(b) What precautions should Mr. Sharma take to avoid such incidences in future?
(c) Which qualities were shown by Mr. Sharma’s father?