Question

The absolute value of charge on the electron was determined by:
(A) J.J Thomson
(B) R.A. Milikan
(C) Rutherford
(D) Chadwick

Answer 1

Hint: Here we will know that the absolute value of charge was determined by R.A. Milikan through the oil drop experiment. further he concluded that the smallest of these values of charge was none other than the charge of the single electron.

Complete answer
Here we will know that the absolute value of charge was determined by R.A. Milikan through the oil drop experiment. Now we will discuss it in detail. So the oil drop experiment was performed by millikan. While using a perfume atomizer tiny drops of oil were sprayed into the transparent chamber and more importantly the oil selected had a very low pressure. Further as the drops travel through the air then some of them fall into the chamber. The space between the place was ionised by radiation. further we will discuss that the electrons from the air attach themselves to oil drops causing them to acquire a negative charge. being charged their speed could be controlled by altering the voltage on plates. Then milikan first let the drops to fall freely without applying voltage to electrodes. Then he further measured the thermal velocity of the drops and then calculated the mass of the drop.
From the experiment they concluded that the one drop fall after varying the voltage and further noting the effect. After repeating the experiment for a number of times he concluded that the charges have the multiple value of the fundamental one. Also, the charge could only assure certain fixed values.
Hence, from this we can say that option B is correct.

Note
Further he concluded that the smallest of these values of charge was none other than the charge of the single electron. He further gave the direct measurement of the electric charge and thus confirmed the existence of the electron.