Question

In the field of electromagnetism, the term “EMI” stands for:
A. Electromotive impact
B. Electromagnetic induction
C. Electromotive inertia
D. none of these

Answer 1

Hint: EMI is a short form of electromagnetic induction that deals with the electromagnetic force and it happens between electrically charged particles. The electromagnetic force is one of the four fundamental forces and shows an electromagnetic field.

Complete step by step answer:Electromagnetism encapsulates the study of the interaction of electrical and magnetic forces. This includes the study of electrical force induction in the presence of magnetic force.

Electromagnetic induction is the phenomenon by which current is generated in a coil due to the change in the magnetic flux in association with it. Similarly, the current is also induced in the circuit or coil when the direction of the current changes when it’s in the span of a magnetic field.
The first method of current induction is adopted in DC inverters while the second method is used in case of AC generators.

Electromagnetic induction was first studied by Michael Faraday in 1980. Based upon his observations, he produced two laws known as Faraday’s laws of Electromagnetic induction.

1) Change in magnetic field of the wire will induce an electromotive force (emf) in it. This emf is called induced emf.

2) Rate of change of flux is equal to the induced emf.
Mathematically, it can be written as,
$E = - N\dfrac{{d\phi }}{{dt}}$
Here, $N$ is the number of turns in the coil, $\phi $ is the magnetic flux and $t$ is the time taken for the flux change.

Thus, the correct option is B.

Note:In this question, the remaining options are electromotive impact and inertia is the imaginary quantities. Both the quantities do not exist. The only proper answer in this particular question is EMI.