Milkman's oil drop experiment gives the value of

Options

A. e
B. m
C. e/m
D. e-m

Explanation

### Step-by-Step Solution:

1. **Understanding the Experiment**: The Millikan oil drop experiment was designed to measure the charge of the electron. It involved a setup with two charged plates (one positive and one negative) and a small hole between them.

2. **Setup Description**: In the experiment, oil droplets were sprayed into the space between the plates. The droplets would fall under the influence of gravity, but when a voltage was applied across the plates, the electric field would exert a force on the charged oil droplets.

3. **Observation of Oil Drops**: The oil drops that passed through the small hole between the plates were observed using a microscope. Some of these drops would be attracted to the negatively charged plate, while others would remain suspended or fall due to gravity.

4. **Ionization of Oil Drops**: To determine the charge on the oil drops, Millikan used radiation to ionize the air, which allowed some of the oil droplets to gain a charge. This ionization was crucial for the experiment as it enabled the measurement of the charge on the droplets.

5. **Calculating Charge to Mass Ratio (E/m)**: By balancing the gravitational force acting on the oil drops with the electric force due to the electric field between the plates, Millikan was able to calculate the charge-to-mass ratio (E/m) of the oil droplets. This ratio is essential in determining the fundamental charge of the electron.

6. **Conclusion**: The main outcome of Millikan's oil drop experiment was the determination of the charge-to-mass ratio (E/m) of the electron, which was a significant contribution to the understanding of atomic structure.

### Final Answer:
The Millikan oil drop experiment gives the value of the charge-to-mass ratio (E/m) of the electron.

---