Electrical energy is transmitted over large distances at high alt… - Vidyadip

Question

Electrical energy is transmitted over large distances at high alternating voltages. Which of the following statements is $($are$)$ correct?

✓

Answer

For a given power level, there is a lower current.
Lower current implies less power loss.

It is easy to reduce the voltage at the receiving end using step-down transformers.

Solution:
Key Concept: Power loss due to transmisssion lines having resistance $(R)$ and $I_{rms}$ current flowing in the circuit is $I^2_{rms} R.$
The power is to be transmitted over the large distances ar high alternating voltages, so current flowing through the wires will be low because of given power $(P).$
For a given power level, we find that
$P = E_{rms}I_{rms} (I_{rms}$ is low when $E_{rms} is high)$
Powor loss $= I^2_{rms} R = low ( \because I_{rms} is low)$
Now at the receiving end high voltage is reduced by using step-down transformers.

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