Name: Current Carrying Conductor Inside a Magnetic Field
Uploaded: 2019-07-19
Duration: 6 min 14 s
Description: A current-carrying conductor behaves as a magnet. So, will it respond when kept in a magnetic field? If yes, how so? Let's discuss in this video.

Question

Explain the construction and working of the following. Draw a neat diagram and label it.
Electric motor

Accepted Answer

Electric motor - It converts electrical energy into mechanical energy.

Principle - When a current-carrying conductor is placed normally in a magnetic field it experiences force that rotates the conductor thus converts into mechanical energy.

Construction -

It consists of an armature coil $A B C D$ mounted on an axle. It also consists of two split rings $P$ and $Q$ with brushes $X$ and $Y$ and a horse-shoe electromagnet $N S$ with a DC source.

The rectangular coil is wound around a soft iron core and is placed between two poles of horse-shoe electromagnet. The coil is free to rotate about its axis. The ends $A$ and $D$ are connected to two split rings, $P$ and $Q$ which are attached with brushes $X$ and $Y$ , respectively. When coil rotates split rings also rotates but brushes remain fixed at their position.

Working-

i. When the current enters the coil $A B C D$ from battery through brush $X$ , coil and finally back to brush $Y$ , the current flows in the coil from $A$ to $B$ upwards and $C$ to $D$ downwards.

ii. So on applying Fleming’s left-hand rule, a force is exerted on arm $A B$ which pushes it downwards and force on arm $C D$ pushes it upwards, thus rotating the coil anticlockwise. As both the forces are equal and opposite in direction, they rotate the coil.

iii. After half rotation, split ring $P$ establishes contact with brush $Y$ and split ring $Q$ establishes contact with brush $X$ , thus the current will flow in $D C B A$ path.

iv. Now force acting on both the arms of the coil will get reversed and the coil will continue to rotate according to Fleming’s left-hand rule and complete the next half rotation in the same direction. Thus, the coil rotates continuously.

Explain the construction and working of the following. Draw a neat diagram and label it.
Electric motor

Important Questions on Effects of Electric Current

Learn and Prepare for any exam you want !

Explain the construction and working of the following. Draw a neat diagram and label it. Electric motor

Important Questions on Effects of Electric Current

Learn and Prepare for any exam you want !

Explain the construction and working of the following. Draw a neat diagram and label it.
Electric motor