An electric charge will experience a force in uniform electric field. Similarly a moving charge experiences a magnetic force (Lorentz) in magnetic field. The SI unit of magnetic field intensity is defined in terms of Lorentz force.
a. Write the expression for magnetic Lorentz force.
b. Mention any two differences between electric and magnetic field.
c. Give an account of work done by Lorentz force on a moving charge and corre sponding change in K.E.

Explanation

` vec F =q( vec V xx vec B)`
b. Electric field is due to a charge, either in motion or at rest. Magnetic field is due to the motion of charge. Direction of electric force is collinear to electric field, direction of magnetic force is perpendicular to magnetic field.
c. As Lorentz force is perpendicular to displacement (velocity), work done is zero and hence there is no change in K.E.