Question

Alternating current is transmitted to distant places at
A. high voltage and low current
B. high voltage and high current
C. low voltage and low current
D. low voltage and high current

Answer 1

Hint: Firstly, we must consider that the A.C. current is travelling to distant places by conducting wire. The wire is not an ideal one. It has some power loss due to various energy being used up while A.C. current travels to distant places.

Complete answer:
According to the given question it is mentioned that the current is travelling to distant places. It is then travelling by a conducting medium which is a conducting wire.
While current travels through the wire it has loss of power mainly due to resistance and various external agents that hamper its efficiency.
We know, that the power loss due to wire is given by,
$P = {I^2}R$
The variables are defined as,
$P = $ Power that is lost while transmission of A.C. current to distant places.
$I = $ current flowing through the wire.
$R = $ resistance of the conducting wire.
The wire is thus having some resistance in it.
So, when we keep the current low, then the value of $P$ will also be less.
Similarly, we have to keep the voltage in the line high so that the power that we get as output is not very less than the input power.
Hence, A.C. current must be in low current and high voltage to be transmitted to distant places.
So, option (A) is correct.

Note:
It must be noted that if a conducting wire is ideal, which has zero resistance then there will be no power loss while transmission. The voltage in the line must be high, or else the output power that we will receive will be very less or might even reach the destination.