Question

3 kw of electrical power is transmitted across the country on the overhead power lines of the 400 kv 'supergrid' and then using the 230 v mains system. Calculate the current required to deliver this power in the 400 kv cables and the 230 v cables?

Answer 1

The current required to deliver 3 kW of power is 7.5 mA for the 400 kV cables and 13.04 A for the 230 V cables. We use the power equation P = V * I to find these values.

Step-by-step explanation:

To calculate the current required to deliver 3 kW of electrical power using the 400 kV 'supergrid' and then via the 230 V mains system, we can use the formula for electrical power:

P = V * I, where P is power in watts, V is voltage in volts, and I is current in amperes.

For the 400 kV transmission lines:

I = P / V = 3,000 W / 400,000 V = 0.0075 A (7.5 mA)

For the 230 V mains system:

I = P / V = 3,000 W / 230 V = 13.04 A

The current in the 400 kV supergrid cables required to deliver 3 kW of power is 7.5 mA, while in the 230 V mains cables, it is 13.04 A.