A tightly-wound, long solenoid has n turns per unit length, a radius r and carries a current i. A particle having charge q and mass m is projected from a point on the axis in a direction perpendicular to the axis. What can be the maximum speed for which the particle does not strike the solenoid?

Explanation

Given current in solenoid =i
Number of turns per unit length = n
Radius of circule `= (r )/(2)`
We know that `(mV^2)/(R ) = qVB`
``rArr V = (qBR)/(m) = (qmu_(0) nir)/(2m).`