Why was the negative plate earthed in milikans oil drop experiment ?
Answers
Answer: In Millikan's oil drop experiment, the motion of oil drop is due to gravitational force and then the motion is due to electric field.
In the first case, when the oil drop moves downwards due to gravitational force, the viscous force acts in upward direction opposing its motion.
When the electric field is switched on, and if the upper plate is positively charged and the lower plate is negatively charged(equivalently electric field is downwards), the oil drop will move upward, assuming the charge of oil drop to be negative.
The voltage was adjusted until the drops were suspended in mechanical equilibrium, indicating that the electrical force and the gravitational force were balanced. Now using the known electric field, Millikan and Fletcher could determine the charge on the oil droplet.
When the electric field is exchanged on, and in case the upper plate is emphatically charged and the lower plate is adversely charged, the oil drop will move upward, expecting the charge of the oil drop to be negative.
Explanation:
- The constrain on any electric charge in an electric field is rise to the item of the charge and the electric field.
- Radiation ionizes the space between the metal plates, which causes the falling oil drops to gain a negative charge as electrons from the discussion join them.
- Millikan's explore is imperative since it built up the charge on an electron.
- Oil drops that are moving up either contain numerous electrons or have a moo mass, as they constrain their involvement due to the electric areas being more prominent than their weight.