Question

9.6 kilo joules of heat is liberated from a heater of resistance 20 ohm in 2 minutes calculate the potential difference across the ends of the heater .​

Answer 1

Answer:

40V

Explanation:

Heat liberated, H = 9.6 kJ = 9600 J

Resistance, R = 20 ohm

time, t = 2 minutes = 120s

Potential Difference, V = ?

$H = \frac{V^2t}{R}\\ \\ \Rightarrow 9600 = \frac{V^2 \times 120}{20} \\ \\ \Rightarrow V^2 = \frac{9600 \times 20}{120} = 1600\\ \\ \Rightarrow V = \sqrt{1600} = 40V$

Potential difference is 40V