Question

Solve the following problem.

A current 4A flows through an automobile headlight. How many electrons flow through the headlight in a time 2hrs?

Answer 1

Given: I = 4 A, t = 2 hrs = 2 × 60 × 60 s

To find: Number of electrons (N)

Formula: I = `"q"/"t"="Ne"/"t"`

Calculation: As we know, e = 1.6 × 10⁻¹⁹ C
From formula,
N = `"It"/"e"=(4xx2xx60xx60)/(1.6xx10^-19)` = 1.8 × 10²³

Number of electrons flowing through the headlight in 2 hrs is 1.8 × 10²³.