Question
Physics Question on Electric Field
The electric field required to keep a water drop of mass in just to remain suspended, when charged with one electron:
A
em/g
B
mg/e
C
emg
D
mg
Answer
mg/e
Explanation
Solution
Here: mass of water drop =m, so, weight of water drop =mg so, mg= electrostatic force applied by the field mg=qE=eE⇒E=emg