Question

a resistor of 50 ohm has a p.d of 100 volt across 1 hour. calculate power and energy​

Answer 1

Explanation:

As we know that Power = V×I = I^2×R= V^2/R

Given

Potential difference = 100 V

Resistance =50 ohm

time = 1 hour = 3600 sec

$Power = \frac{ {</strong><strong>V</strong><strong>}^{2} }{</strong><strong>R</strong><strong>} \\P = \frac{ {100}^{2} }{50} \\ P = \frac{10000}{50} \\ </strong><strong> </strong><strong> </strong><strong> </strong><strong>P = 200 \: watt$

Now work done = energy = Power × time

$</strong><strong> </strong><strong>Energy</strong><strong> \: = Power \times time \\ </strong><strong>E</strong><strong> = 200 \times 3600 \\ </strong><strong>E</strong><strong> = 720000 \: \: joule \\ </strong><strong>E</strong><strong> = 0.72 \times {10}^{ 6} joule \\ </strong><strong>E</strong><strong> = 0.72 \: mega \: joule$