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Power loss in transmission cables of resistance Rc delivering power P at voltage V is P²Rc/V². To minimise this loss, electrical power is transmitted at:
Ahigh voltage and high current
Bhigh voltage and low current
Clow voltage and high current
Dlow voltage and low current
Answer & Solution
Correct answer: B. high voltage and low current
Cable loss P_c = P²R_c/V². For a fixed delivered power P, raising V lowers the current and hence the I²R_c loss — so power is sent at high voltage and low current.
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