Question

If the current `I` through a resistor is increased by `100%` (assume that temperature remains unchanged), the increase in power dissipated will be :
A. 1
B. 2
C. 3
D. 4

Answer 1

Correct Answer - C
`P_1 = I^2 R, P_2 = (2 I)^2 R = 4 I^2 R` (as 100% increase in current means that current becomes `2 I`).
Increase in power dissipated `= P_2 - P_1 = 4 i^2 R - I^2 R = = 3 i^2 R = 3 P_1`
% age increase in power dissipated `= (3 P_1)/(P_1)xx 100 = 300 %`.