Table of Contents
What happens when the coil rotates?
When the coil of a motor is turned, magnetic flux changes, and an emf (consistent with Faraday’s law of induction) is induced. The motor thus acts as a generator whenever its coil rotates. This will happen whether the shaft is turned by an external input, like a belt drive, or by the action of the motor itself.
Why does a coil rotate in a magnetic field?
The coil of wire is mounted in the gap between the two magnets. The split rings make electrical contact with the coil and reverse the current every half turn. When an electric current flows through the coil, a force is exerted on the coil, causing it to spin.
Why does coil not rotate continuously?
Once the coil gets to the upright position, there is no turning force on it because the electromagnet of the coil is lined up with the permanent magnets. If the current in the coil were constant, the coil would stop in this position. However, to keep it spinning, the commutator breaks contact in this position.
In which direction will the coil rotate?
In the diagram above, based on Fleming’s left hand rule, the right side of coil experiences an induced force in downward direction while the left side of coil experiences an induced force in the upward direction. This creates a clockwise moment about the pivot (axis of the coil) and coil rotates in clockwise direction.
Why do coils rotate?
A coil of wire carrying a current in a magnetic field experiences a force that tends to make it rotate. This effect can be used to make an electric motor.
Why does a coil rotate continuously?
The forces on each side of the coil are in the opposite directions to one another, so the coil turns (4). The commutator reverses the current around the coil with every half turn (5) meaning that the coil is pushed in the same direction every half turn, and thus continues to rotate (6).
Why rotating the coil produces an output voltage?
As the coil rotates between the poles of the magnet, the sides of the coil cut through the magnetic field and so a current flows in the coil. The faster the coil rotates the faster will it cut the magnetic field and the bigger will be the output voltage.