Question

working, construction, principal of elictric motor

Answer 1

An electric motor is a device which converts electrical energy into mechanical energy. A common motor works on direct current. So, it is also called DC motor
Principle

When a rectangular coil carrying current is placed in a magnetic field, a torque acts on the coil which rotates it continuously.

When the coil rotates, the shaft attached to it also rotates and thus it is able to do mechanical work.

Answer 2

$\huge\bold{Electric \: motor}$

A motor is a device which converts electrical energy into mechanical energy. Every motor has a shaft or spindle which rotates continuously when current is passed into it.

$\textbf{Principle \: of \: motor}$

A Motor Works on the principle that when a rectangular coil is placed in a magnetic field and current is passed through it a force act on the coil which rotates it continuously.

$\textbf{Constuction \: of \: motor}$

★ It consist of a single loop of an insulated copper wire in the form of a rectangle which is known as Armature coil.

★ Armature coil is placed between two pole places of the strong magnet which provide strong magnetic field which is known as strong magnetic field.

★$\textsf{Split \: ring \: type \: Commutator - }$
it consist of two half of magnetic ring. The two ends of armature coil are connected to these two half of ring. The commutator reverse the direction of current in armature coil.

★$\textsf{ Brushes- }$ Two carbon brushes press against the commutator. These brushes act as contact between commutator and terminal battery.

★$\textsf{ Battery- }$ It is connected across carbon brushes. It supplies current to the armature coil.

$\textbf{Working \: of \: motor}$

Working of Electric Motor

★When current flow through coil,arm AB and CD experience magnetic force.

★ According to Fleming’s Left hand rule,arm AB of coil experiences force in downward direction and arm CD experiences force in upward direction.

★ Both these forces are equal and opposite.

★ 2 equal and opposite forces acting at different position of armature constitute a couple.

★ The couple rotate the coil in clockwise direction until the coil is in vertical position.