11 kW of electric power can be transmitted to a distant station at (i) 220 V (ii) 22000 V. Which of the two transmission modes be preferred and why ? Support your answer with calculations.

Explanation

`P = 11 kW = 11000 W`
(i) `V_(1) = 220 V, :. I_(1) = (P)/(V_(1)) = (11000)/(220) = 50 A`
Power loss `= I_(1)^(2) R = (50)^(2) R = 2500 R` watt
(ii) `V_(2) = 22000 V :. I_(2) = (P)/(V_(2)) = (11000)/(22000) = 0.5 A`
Power loss `= I_(2)^(2) = (0.5)^(2) R = R//4` watt
Power loss becomes `1//10000` times the power loss in the first case. Hence transmission at high voltage should be perferred.