A very long wire ABDMNDC is shown in figure carrying current I. AB and BC parts are straight , long and at right angle. At D wire forms circular turn DMND of radius R . AB, BC parts are tangential to circular turn at N and D . Magnetic field at the centre of circle is :
The electric fields of two plane electromagnetic plane waves in vacuum are given by
and
At t = 0, a particle of charge q is at origin with velocity (c is the speed of light in vacuum
). The instantaneous force experienced by the particle is:
An electron gun is placed inside a long solenoid of radius R on its axis. The solenoid has n turns / length and carries a current I. The electron gun shoots an electron along the radius of the solenoid with speed . If the electron does not hit the surface of the solenoid, maximum possible value of is (all symbols have their standard meaning) :