Millikans Oil Drop Experiment 1. Performing this experiment in air is tricky bec
ID: 1382538 • Letter: M
Question
Millikans Oil Drop Experiment
1. Performing this experiment in air is tricky because air itself can be ionized and because of this, the beads may discharge over time, leading to erroneous results. If you could somehow put the entire apparatus in unionizable gas, what term(s) in your equations for the charges or for the individual forces would need to be modified?
2. Along the same lines, one might imagine we may be able to have even better results if we could do this in a vacuum! Will this strategy work?
3. Suppose charge was not discrete but rather came in continuous form and infinitesimally divisible. We would still get a quantity of charge on each bead and moreover still be able to see a terminal velocity both with the E field pointing up and down. If this was the case, what would change in our results?
Explanation / Answer
(1) performing the Millikan's oil experiment is given as :
Initially the oil drops are allowed to fall between the plates in the absence of electric field. Due to gravity they
accelerate first, but gradually slowdown because of air resistance.
The terminal velocity v1 in the absence of an electric field is calculated as :
v1 = l1 / t1 { eq. 1 }
where 'l1' is the distance travelled by the oil drop and