Question

Discuss the similarities and the differences between the electrical force on a charge and magnetic field force on a charge. Please make a short and simple answer.

Answer 1

Similarities:

1. Both electric and magnetic forces are propagated by fields which travel at the speed of light in vacuum. So both are non contact forces.

2. Both electric force and magnetic force can be attractive as well as repulsive.

3. Both obey inverse square law of force.

Differences:

1. The source of electric force is a static charge distribution whereas source of magnetic force is current.

2. The field lines of electric force originate from positive charge and end at negative charge but the field lines of magnetic force forms closed loops.

3. The work done by electric force can increase the kinetic energy of a charged particle but the work done by magnetic force can never increase the kinetic energy of the charged particle.

4. Opposite charges attract each other and same charges repel each other but parallel current attracts each other and opposite currents repel each other.

5. The source of electric force is can be a single charge unit +Q but magnetic monopoles don't exist.

6. The electric force on a charge particle acts on the plane of motion of the charged particle but magnetic force always act perpendicular to the plane of motion of the charged particle.

7. Electric force field produced due to static charge distribution is conservative in nature but magnetic field is non conservative.