Question

How many electrons move through a single 35.0 W headlight? How many electrons pass through it each second

Answer 1

The power of a current

$$P=VI$$

The current

$$I=\frac{P}{V}$$

Hence, the number of electrons passing through the bulb

$$N=\frac{q}{e}=\frac{It}{e}=\frac{Pt}{Ve}$$

$$N=\frac{35.0*1}{220*1.6*10^{-19}}=9.94*10^{17}$$