WAEC - Physics (1996 - No. 52)
Calculate the amount of heat generated in an external load of resistance 8Ω if an alternating current of peak value 5A is passed through for 100s.
20,000J
10,000J
5,000J
4,000J
200J
Explanation
E = I\(_{rms}\)\(^2\)Rt
I\(_{rms}\) = \(\frac{I_o}{\sqrt{2}}\) = \(\frac{5}{\sqrt{2}}\) = 3.5355
E = 12.5 x 8 x 100 = 10,000J