Question

Pylon cables in the National Grid have some resistance. Power (watts) = Current2 (amperes) x Resistance (ohms) Looking at the power equation above, can you explain why transmitting electricity at a very high voltage is beneficial? Hint: Think about the equation Power (W) = P.D (V) x Current (A) Equation

Answer 1

Answer: To reduce resistance in order to achieve high efficiency of electrical transmission.

Explanation: Given that the

Power P = Current I^2 x Resistance R

That is,

P = I^2 × R

Also, remember that

P = IV

Where V = voltage.

Looking at the power equations above, we can explain why transmitting electricity at a very high voltage is beneficial. Because Transmitting at very high voltage will make current to be transmitted or flow through the wire with a very small magnitude. Since Voltage is inversely proportional to current from the formula

P = IV

Electricity will flow in any diameter of cable use with a low resistance thereby, increasing the efficiency of the electricity transmission by reducing the heat that might be generated as a result of electrical resistance during the course of transmission.