Question

Please answer these 3 questions...thank you!

1. List two ways in which electric and magnetic fields and forces are similar.
2. List two ways in which electric and magnetic fields and forces are different.
3. If moving charges create a magnetic field, explain how a bar magnet has a magnetic field.

Answer 1

• Similarity

1. Electric and magnetic fields and forces both are vector quantities i.e they all possess magnitude as well as a direction.

2. Electric fields are produced by two kinds of charges, positive and negative similarly magnetic fields are associated with two magnetic poles north and south.

• Difference

1. Electric force is either parallel or anti-parallel to the direction of Electric field whereas Magnetic force is perpendicular to the direction of magnetic field.

2. Electric field is being generated by a charge doesn't matter whether at rest or moving whereas magnetic field can only be generated by a moving charge and not stationary.

• Explanation

A magnetic field is generated from the moving charges due to the Maxwell's laws which tells us that changing magnetic fields generate electric fields and changing electric fields generate magnetic fields. Yet a bar magnet can produce a magnetic field without any charged particle moving around. The reason is because particles/ atoms/ molecules have magnetic dipole moments inherent in their nature, which have elementary magnetic fields. In a permanent magnet the domains after being oriented in a direction retain it because they are in the lowest energy state of the solid when oriented. The magnetic field is the same type of field for both the cases.