Question

A generator produces 240kW of electric power at7.2 kV . The current is transmitted to a remote village through wires with a total resistance of15 ohms ? .

Part A

What is the power loss due to resistance in the wires?

Express your answer with the appropriate units.

P=

Part B

What is the power loss if the voltage is increased to 30 kV ?

Express your answer to two significant figures and include the appropriate units.

P=

Answer 1

POWER GENERATED = 240KW

VOLTAGE = 7.2 KV

P = VI

I = P/V = 240/7.2 = 33.33 A

RESITANCE OF WIRE = 15 OHM

SO POWER LOSS IN WIRES = I²R

                                                =33.3²*15 = 16.66 KW

NOW VOLTAGE IS INCREASED TO 30KV.

CURRENT I = P/V = 240/30 =8A

SO POWER LOSS = I²R = 8²*15 = .96 KW