A tiny spherical oil drop carrying a net charge q is balanced in still air with a vertical uniform electric...

Question

A tiny spherical oil drop carrying a net charge q is balanced in still air with a vertical uniform electric field of strength 81 7 10^5 Vm^ -1 . When the field is switched off, the drop is observed to fall with terminal velocity 2 10^ -3 m ,s^ -1 . Given g = 9.8 m ,s^ -2 , viscosity of the air = 1.8 10^ -5 Ns ,m^ -2 and the density of oil = 900 kg ,m^ -3 , the magnitude of q is

Accepted Answer

(D)

JEE Advanced 2010 Physics question

Solution

See the full step-by-step solution