Question

Millikan's famous oil drop experiment established that

• A. Electric charge is quantized
• B. Mass is quantized
• C. Energy of an atom is quantized
• D. Workfunction is quantized

Hint:

Millikan’s oil drop experiment measured the elementary charge \(e\), proving charge quantization.

Answer 1

The Correct Option is A

Step 1: Description of the experiment.
Millikan (1909) suspended tiny charged oil droplets between two electrically charged plates and observed their motion under gravity and an applied electric field.
Step 2: Key finding.
He found that the charge on each droplet was always an integer multiple of a smallest value: \[ q = n \times e, \quad e = 1.602 \times 10^{-19} \, C \] Thus, establishing that electric charge is quantized.
Final Answer: \[ \boxed{\text{Electric charge is quantized}} \]