
An experimenter’s diary reads as follows, a charged particle is projected in a magnetic field of . The acceleration of the particle is found to be . Find the value of .

Important Questions on Magnetic Effect of Current
A particle of mass and positive charge , moving with a uniform velocity , enters a magnetic field as shown in the figure. Find the radius of the circular arc it describes in the magnetic field. Find the angle subtended by the arc at the centre. How long does the particle stay inside the magnetic field? Solve the three parts of the above problem if the charge on the particle is negative.

A particle of mass and charge is projected into a region having a perpendicular magnetic field . Find the angle of deviation (figure) of the particle as it comes out of the magnetic field if the width of the region is very slightly smaller than
and

The figure shows a convex lens of focal length lying in a uniform magnetic field of magnitude parallel to its principal axis. A particle having a charge and mass is projected perpendicular to the plane of the diagram with a speed of . The particle moves along a circle with its centre on the principal axis at a distance of from the lens. The axis of the lens and of the circle are the same. Show that the image of the particle goes along a circle and find the radius of that circle.





An electron gun emits electron of energy travelling in the positive direction. The electrons are required to hit the spot where and the line makes an angle of with the axis, as shown in the figure. A uniform magnetic field parallel to exists in the region outside of electron gun. Find the minimum value of needed to make the electron hit . [Take mass of electron ]
