An alternating current with a peak value of 5A passes through a resistor of resistance 10Ω. Calculate the rate at which energy is dissipated in the resistor
250W
125W
50W
35.4W
12.5W
Explanation
Video Explanation
No video available
Post your Contribution
Discussions (6)

I fink d ans is 125
P=Irms^2*R
where Irms=Io/root2
Irms=5/root2
(5/root2)^2 *10
=125w

Greetings, The Myschool Team.
The correct answer is B(125W) and not A(250W). In alternating current circuits, the current value used for determining energy dissipated is the root mean square (rms) value of current, not the peak current. This can be seen from the definition of rms current below:
"Root Mean Square (RMS) value of AC current is defined as the steady or DC current which when flowing through a circuit for a given time period produces the same heat as produced by the AC current flowing through the same circuit for the same time period. "
Source: https://electricalbaba.com/
RMS value= 5sin 45 = 5√2/2 = 3.54A
P = I²R = (5√2/2)² × 10
= 25/2 × 10
= 125W
Thus, the correct answer is B (125W) and not A(250W). Thank you.



