Which experiment is responsible for finding out the charge on an electron?

The correct answer is Millikan's oil drop experiment.

Key Points

Charge on the Electron:

• R.A. Millikan (1868-1953) devised a method known as the oil drop experiment (1906-14), to determine the charge of the electrons.
• He found the charge on the electron was – 1.6 × 10^-19 C. 
• The presently accepted value of the electrical charge is – 1.6022 × 10-19 C.

Additional InformationPhotoelectric Experiment:

• In the photoelectric experiment, a metal plate is illuminated with light of a certain frequency or energy, and the number of electrons emitted from the plate is measured.
• The intensity of the light is kept constant, but the frequency or energy of the light is varied.
• The number of emitted electrons is found to increase with the frequency or energy of the light.

Rutherford's α-ray scattering experiment:

• In this experiment, firing a beam of alpha particles, which are positively charged particles that are emitted by radioactive materials, at a thin sheet of gold foil.