Question

Ajit had a high tension tower erected on his farmland. He kept complaining to the authorities to remove it as it was occupying a large portion of his land. His uncle, who was a teacher, explained to him the need for erecting these towers for efficient transmission of power. As Ajit realized its significance, he stopped complaining.
Answer the following questions:
(a) Why is it necessary to transport power at high voltage?
(b) A low power factor implies large power loss. Explain.
(c) Write two values each displayed by Ajit and his uncle.

Answer 1

(a) If high voltage is used to transmit power, then the current through the wire will be less as $I=\frac{P}{V}$. Hence, the power loss = $I^{2}R$ will also be less.

(b) The power is given as $P=VI\cos \varphi$, where $\cos \varphi$ is the power factor. To supply a given power at a given voltage of transmission, if $\cos \varphi$ is small, then according to the above equation, current $I$ has to be large. This leads to a large power loss caused by heat which is given as $H=I^{2}R$. Hence, a low power factor implies large power loss.

(c) Values displayed by Ajit: Understanding in nature and proactive.

Values displayed by uncle: Patience and intelligence