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Question
Ajit had a high tension tower erected on his farm land. 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 realised 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.
Solution
(a)If high voltage is used to transmit power, then the current through the wire will be less as I = P/V. Hence, the power loss = I2R will also be less.
(b)The power is given as P = VI cosθ, where cos is the power factor. To supply a given power at a given voltage of transmission, if cos 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 = I2R. 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
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