Who evaluted the mass of electron indirectly with help of charge:

Options

A. Thomson
B. Millikan
C. Rutherfored
D. Newton

Answer

To solve the question of who evaluated the mass of the electron indirectly with the help of charge, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Scientists Involved**: The question provides a list of scientists: Thomson, Millikan, Rutherford, and Newton. We need to determine which of these scientists is associated with the evaluation of the mass of the electron.

2. **Understanding Millikan's Contribution**: Robert Millikan is known for his oil drop experiment, which was crucial in determining the charge of the electron. By measuring the force on tiny charged oil droplets in an electric field, he was able to calculate the charge of the electron.

3. **Relating Charge to Mass**: Millikan's experiment allowed for the determination of the charge-to-mass ratio of the electron. By knowing the charge of the electron and using the relationship between electric force and gravitational force, he could indirectly evaluate the mass of the electron.

4. **The Oil Drop Experiment**: In the oil drop experiment, charged oil droplets were suspended between two plates in an electric field. By adjusting the electric field strength, Millikan was able to balance the gravitational force acting on the droplets with the electric force, leading to the calculation of the charge on the droplets.

5. **Conclusion**: Based on the above analysis, we conclude that Robert Millikan evaluated the mass of the electron indirectly with the help of charge through his oil drop experiment.

### Final Answer:
**Robert Millikan** evaluated the mass of the electron indirectly with the help of charge.

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