Question

The magnetic effect of current was discovered by:
(a). John Ambrose Fleming
(b). Hans Christian Oersted
(c). Michael Faraday
(d). Andre-Marie Ampere

Answer 1

- Hint: There are laws named after the physicist who discovered that magnetic fields are created when an electric current flows around a conductor. Magnetic effect of current and current was discovered by different people.

Complete step-by-step answer:
Before we discuss the discoverer of magnetic effect of current, let us understand what is current and how a magnetic field is created around it.
An electric current is a flow of charge carriers that flow through a conductor or a semiconductor. The unit of current is Ampere denoted by A. The charge carriers are electrons in conductors and electrons and holes in semiconductors. On the other hand, the magnetic field is the result of electric charges in motion and it can be measured in tesla.
The concept of magnetic effect of current was discovered by Hans Christian Oersted in 1820 using an experiment which uses SNOW rule, which states in case current in a conductor flows from south to north, then the north of the magnetic needle deflects west.
According to H.C Oersted, a magnetic field is created whenever current flows around a conductor. In the experiment, he used two straight wires and joined them using a battery and plug so that it creates a circuit and current flows. A magnetic compass needle is used. Place the straight wire in parallel and above the magnetic compass needle. When the current flows from north to south, the needle gets deflected towards east. Similarly, when the current flows from south to north, the needle gets deflected toward the west.
This can be illustrated using the below diagram:

Note: Magnetic field is inline proportional to the current passing through the conductor. Oersted discovery is the first to link electricity and magnetism.
John Ambrose Fleming discovered Right hand rule and left hand rule.
Michael Faraday discovered electromagnetic induction.
Andre-Marie Ampere is related to electromagnetism.