Calculate the work done in a resistor of 20 ohm carrying 5A of current in 3 hours.a)1.5Jb)15Jc)1.5kWhd)15kWhCorrect answer is option 'C'. Can you explain this answer?

Question

Answer

To find power: P=I²R=5²*20=500W=0.5kW.
To find Work done: W=Pt=0.5*3=1.5kWh.

Answer

Energy = power × time

power = I*2 ×R

energy= I*2 × R × t
energy = 5*2 × 20 × 3 wh
energy = 25× 20×3 wh
energy = 1500 wh
energy = 1.5kwh

Answer

To calculate the work done in a resistor, we can use the formula:

Work = Power × Time

First, let's find the power dissipated in the resistor using the formula:

Power = Current^2 × Resistance

Given:
Resistance = 20 ohm
Current = 5A

Substituting the values into the formula:
Power = (5A)^2 × 20 ohm = 25 × 20 = 500 watts

Now, let's convert the time from hours to seconds:
Time = 3 hours × 60 minutes/hour × 60 seconds/minute = 10,800 seconds

Substituting the values into the work formula:
Work = 500 watts × 10,800 seconds = 5,400,000 watt-seconds (or joules)

Finally, let's convert the work from joules to kilowatt-hours (kWh):
1 kilowatt-hour = 3,600,000 joules

Work in kilowatt-hours = 5,400,000 joules / 3,600,000 joules/kWh = 1.5 kWh

Therefore, the correct answer is option C) 1.5 kWh.

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