Question

An electric charge in uniform motion produces:
(A). An electric field only
(B). A magnetic field only
(C). Both electric and magnetic fields
(D). No such field at all

Answer 1

Hint: An electric charge applies a coulomb force in all three dimensions on other charges which is felt by other charges in the form of an electric field electric field. The fields of electricity and magnetism are interlinked with each other. In fact, a changing electric field gives rise to a changing magnetic field and vice versa.

Complete step by step answer:

An electric charge always exerts a force known as the Coulomb force in all three dimensions upon other electrical charges. This force is felt by the other charged particles as the effect of an electrical field that originates from the first charge and travels through the medium in the form of a wave to reach them.
This electric force and, hence, electric field is produced by an electrical charge irrespective of its motion.
Electricity and magnetism are phenomena that are interlinked between each other. In fact they are said to be essentially a part of the bigger field of study, that is, electromagnetism. It has also been found out that a changing magnetic field gives rise to a changing electric field and vice versa.
Hence, when an electric charge is in uniform motion, it produces an electric field that is also changing in position and travelling through space. Thus, this changing electric field produces a changing magnetic field. Hence, in essence, the electric charge in uniform motion produces the magnetic field.
Hence, the electric charge in uniform motion produces both electric and magnetic fields.
Hence, the correct answer is C) both electric and magnetic fields

Note: Students must keep in mind that a stationary electric charge does not produce a changing electric field and hence cannot produce a magnetic field. If only the charge is in motion, then a magnetic field is produced. This concept is often applied in trick questions to lead students down the wrong thinking path.
The concept that electricity and magnetism are linked has been proved by many concepts and experiments including Faraday’s law of electromagnetic induction and Oersted’s experiment where he proved that a current carrying wire produces a magnetic field around it.