4.E Millikan's Oil Drop Experiment Flashcards
What equipment do we need for the Millikan’s Oil Drop experiement?
An atomiser
A pair of conducting plates
A power supply
What happens as the drops leave the atomiser?
The drops become charged due to friction.
What happens to the drops when the circuit is off?
The drops will fall straight down to the bottom plate due to gravity.
What happens to the oil drops when the circuit is switched on.
With potential difference between the 2 plates there is an electric field that is created. It exerts a force on the oi drops. By finding the right potential difference we can balance the drops mid air.
What happens when pd is increased?
The drops will accelerate towards the plate of opposite charge to the drops,which must be the top one for the experiment to work. This is due to the greater strength of the electric field.
What happens when distance between plates is increased?
The pd decreases and so the drops will accelerate towards the bottom plate.
Show the coming up with the equation of q = mgd/v
weight = electrostatic force mg = EQ Q = mgd/v
What happens when the distance between the plates is decreased?
The electric field strength is increased and so the drops will accelerate towards the top plate.
What happens when pd is decreased? What forces are unbalanced and what does it cause?
The electric field strength decreases so that the weight is greater than electrostatic force. The drops will fall towards the bottom plate.
