Question :(i) Why is an alternating current (A.C.) considered to be advantageous over a direct current (D.C.) for the long-distance transmission of electric power?
(ii) How is the type of current used in household supply different from the one given by a battery of dry cells?
(iii) How does an electric fuse prevent the electric circuit and the appliances from possible damage due to short-circuiting or overloading?
The correct answer is -(i) An alternating current (A.C.) is considered advantageous over a direct current (D.C.) for the long-distance transmission of electric power due to the following reasons:
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The voltage of A.C. can be increased or decreased with the help of a transformer, which is not possible with D.C.
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A.C. can travel long distances with less power loss due to the skin effect. In contrast, D.C. has higher power loss due to resistance.
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A.C. can be easily converted into high voltages for transmission over long distances, and then converted back into low voltages for household use.
(ii) The type of current used in household supply is alternating current (A.C.), which is different from the direct current (D.C.) given by a battery of dry cells. The key differences between the two types of current are as follows:
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A.C. changes direction periodically, while D.C. flows in only one direction.
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The voltage of A.C. can be easily increased or decreased with the help of a transformer, while D.C. cannot.
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A.C. is more suitable for the long-distance transmission of power, while D.C. is more suitable for low-voltage applications.
