Question

A coil carries a current in a magnetic field. The coil experiences a turning effect. Which device uses this effect?
A) A DC motor
B) An electromagnet
C) A relay
D) A transformer

Answer 1

Hint: A straightforward electric machine can be manufactured utilizing a coil of wire that is allowed to turn between two inverse attractive shafts. At the point when an electric flow moves through the coil, the loop encounters a force and moves.

Complete step by step answer:
We can see what concept do the various machines work on:
A simple DC motor uses a stationary set of magnets within the stator, and a coil of wire with a current running through it to get an electromagnetic field aligned with the centre of the coil. One or more windings of insulated wire are wrapped round the core of the motor to concentrate the field of force.
All electromagnets work on the principle that an electrical current during a wire produces a force field. Of course it's remarkably straightforward to create an electromagnet. Simply coil a length of wire round a chunk of iron, like a protracted iron nail, and pass an electrical current through the wire. When this flows a field of force is made and therefore the iron becomes magnetised.
Relays are switches that open and shut circuits electro mechanically or electronically. Relays control one circuit by opening and shutting contacts in another circuit. As relay diagrams show, when a relay contact is often open (NO), there's an open contact when the relay isn't energized.
A transformer is an electrical apparatus designed to convert AC from one voltage to a different. It may be designed to "step up" or "step down" voltages and works on the magnetic induction principle.

Hence the correct option is A.

Note: We must take care of the fact that an electric motor converts electrical energy into mechanical energy. Basically, we ought to have the basic theoretical knowledge about the working principles of various daily use equipment.