How do electric motors work? - Higher - OCR 21st CenturyElectric motors
Electromagnetism is caused by the magnetic fields around wires carrying an electric current. The induced magnetic field of a wire can interact with other nearby magnets, producing a force.
A coil of wire carrying a current in a magnetic fieldArea surrounding a magnet that can exert a force on magnetic materials. experiences a force that tends to make it rotate. This effect can be used to make an electric motor.
Explaining an electric motor
The diagram shows a simple motor using direct currentAlso called dc. An electric current that flows in one direction only. (dc).
Starting from the position shown in the diagram of the dc motorAn electrical device that uses direct current to produce a turning effect.:
the current in the left hand part of the coil causes a downward force, and current in the right hand part of the coil causes an upward force
the coil rotates anti-clockwise because of the forces described above
When the coil is vertical, it moves parallel to the magnetic field, producing no force. This would tend to make the motor come to a stop, but two features allow the coil to continue rotating:
the momentum of the motor causes it to continue to rotate a little
a split ring commutatorPart of a dc electric motor that reverses the direction of the current every half turn of the coil. changes the current direction every half turn
This means that the current in the left hand part of the coil still causes a downward force, and current in the right hand part of the coil still causes an upward force.
This means that the motor effect forces continue to cause anti-clockwise rotation of the coil.
Electric motors affect almost every aspect of daily life. They can be found in homes, schools and even in cars.