Question:medium

In Milikan’s experiment, a static electric charge on the oil drops was obtained by shining X-rays. If the static electric charge on the oil drop is –1.282 × 1018C, calculate the number of electrons present on it.

Updated On: Jan 21, 2026
Show Solution

Solution and Explanation

Given:

Charge on oil drop, Q = −1.282 × 10−18 C
Charge of one electron, e = 1.602 × 10−19 C


Step 1: Use relation between charge and number of electrons

Q = n × e

n = Q / e


Step 2: Calculate number of electrons

n = (1.282 × 10−18) / (1.602 × 10−19)

n = 8


Final Answer:

Number of electrons present on the oil drop = 8

Was this answer helpful?
0