Question

If a current of 5 A flows through a resistor of 12 ohms, find the power developed and the energy dissipated in 2 minutes.

a) Power: 60 W, Energy: 720 J

b) Power: 120 W, Energy: 240 J

c) Power: 240 W, Energy: 480 J

d) Power: 360 W, Energy: 720 J

Answer 1

The power developed and the energy dissipated by the current in 2 minutes is 300 watts and 36,000J respectively.

The power generated by the flowing current can be calculated as the product of the voltage and current i.e. P = V X I.

V = IR

V = 5 × 12 = 60V

P = 60V × 5A = 300watts

The amount of energy provided by electric current can be calculated by multiplying the watts (J/s) by seconds to yield joules.

Energy = 300 × 120 = 36000J