Question

In a Millikan’s oil drop experiment, the charge on an oil drop is calculated to be \( 6.35 \times 10^{-19} \, \text{C} \). The number of excess electrons on the drop is:

• A. 32
• B. 42
• C. 6
• D. 4

Hint:

The number of excess electrons on an oil drop is calculated by dividing the total charge by the charge of a single electron.

Answer 1

The Correct Option is C

Step 1: Formula for number of excess electrons.
The number of excess electrons is given by: \[ n = \frac{q}{e} \] where \( q \) is the total charge and \( e \) is the charge of an electron.
Step 2: Calculation.
Substituting the given charge of the drop and the charge of an electron: \[ n = \frac{6.35 \times 10^{-19}}{1.6 \times 10^{-19}} = 6 \]
Final Answer: \[ \boxed{6} \]