Question

As more resistors are added in series across a constant voltage source, the power supplied by the source: A) does not change. B) increases. C) decreases. D) is always zero

Answer 1

As series resistors are added, the resistance is added directly so the total resistance will be equal to

$R_T = R_1+R_2+R_3... R_{\infty}$

Since the power is determined as

$P = \frac{V^2}{R}$

We have there that

$P \propto \frac{1}{R}$

The power is inversely proportional to the increase in resistance, so it will tend to decrease as more resistors are added in series.

The correct answer is: C.