Question

If the current flowing through a circuit of constant resistance is doubled, the power dissipated by that circuit willa) decrease to one half of what it wasb) decrease to one fourth of what it wasc) quadruple in magnituded) double in magnitude

Answer 1

Answer:

c) quadruple in magnitude

Explanation:

The power dissipated in the circuit is given by:

$P=I^2 R$

where

I is the current in the circuit

R is the total resistance of the circuit

In this problem:

- The current is doubled: I' = 2 I

- The resistance is kept constant: R' = R

So, the power dissipated is

$P' = (I')^2 R' = (2I)^2 R=4 I^2 R=4 P$

so, the power dissipated increase by a factor 4 (quadruples).