A large parallel plate capacitor has vertical plates with a potential difference of `2000 V` between them. Oil drops are sprayed between the plates. Few drops are observed to move with uniform velocities in directions inclined at `45^(@),33.7^(@) and 18.4^(@)` to the vertical. The space between the plates has air and mass of each drop is `m = 3.3 × 10^(-15) kg`. Separation between the plates is 3 cm.
(a) Explain the observations.
(b) From the above observations estimate the magnitude of smallest charge in nature. `tan (33.7^(@)) = 0.67 and tan (18.4^(@)) = 0.333`

Answer

(b) `1.62 xx 10^(-19) C`