Terminal velocity

In Milikan's oil drop experiment, a charged drop falls with terminal velocity V. If an electric field E is applied in vertically upward direction then it starts moving in upward direction with terminal velocity 2V. If magnitude of electric field is decreased to (E)/(2) , then terminal velocity will become

Sixty four spherical rain drops of equal size are falling vertically through air with a terminal velocity 1.5ms^(-1) . If these drops coalesce to form a big spherical drop, then terminal velocity of big drop is:

Eight identical droplets, each falling under gravity in the earth's atmosphere with terminal velocity v , combine to form a single drop. The terminal velocity of single drop and drag force on it are calculated. Find the correct statement from the following.

A spherical ball falls through viscous medium with terminal velocity v . If this ball is replaced by another ball of the same mass but half the radius, then the terminal velocity will be (neglect the effect of buoyancy.)

At a given place two rain drops of volumes V and 8V are falling down with terminal velocities. Their terminal velocities are in the ratio

At a given place two rain drops of volumes V and 8V are falling down with terminal velocities.Their terminal velocities are in the ratio

The diameter of ball A is half of that of B. The ratio of their terminal velocities will be

The ratio of the terminal velocities of two drops of radii R and R//2 is