1. Tardigrade
  2. Question
  3. Physics
  4. In Millikan's oil drop experiment ; a drop of charge Q and radius r is kept constant between two plates of potential difference of 800V. Then charge on other drop of radius 2r which is kept constant with a potential difference of 3200 is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. In Millikan's oil drop experiment ; a drop of charge $Q$ and radius r is kept constant between two plates of potential difference of $800V$. Then charge on other drop of radius $2r$ which is kept constant with a potential difference of $3200$ is

Dual Nature of Radiation and Matter

Solution:

Using $QE = \frac{4 \pi}{3} r^3 \, \rho g$ i.e . Q$\frac{V}{t} = \frac{4 \pi}{3} r^3 \rho g$ ...(i)
also Q $\times \frac{V'}{l} = \frac{4\pi}{3} (2r)^3 \, \rho g$ ....(ii)
Dividing equation $(i)$ by equation $(ii)$ $\frac{QV}{Q'V'} = \frac{1}{8} $
or $Q' = \frac{QV}{V'} \times 8 = \frac{Q \times 800 \times 8}{3200} $ = 2Q