Question

A circuit maintains a constant resistance. If the current in the circuit is doubled, what is the effect on the power dissipated by the circuit?

 The power dissipated is quadrupled The power dissipated is doubled.

 The power dissipated remains constant. 

 The power dissipated is reduced by a factor of 4.

 The power dissipated is reduced by a factor of 2.

Answer 1

The power in the circuit is given by the relation is,

$$ P=I^{2} R $$

Here, \(I\) is the current, \(R\) is the resistance.

If the current in the circuit is doubled then, the power dissipated in the circuit is given by

$$ \begin{aligned} P &=I_{0}^{2} R \\ &=(2 I)^{2} R \\ &=4 I^{2} R \end{aligned} $$

If the current in the circuit is doubled, the power dissipated by the circuit is quadrupled.