GCSE Physics Unit 3 - Electromagnetism

P3.3.1 - The Motor Effect

• Placing a wire with a current in a magnetic field (between two magnets) makes the wire experience a force called "The Motor Effect".
• This force is at its maximum if it is held at 90 degrees to the magnetic field.
• The force can increase by:

 - Increasing the strength of the magnetic field

 - Increasing the size of the current.

• The direction of the force is reversed if either direction of the current or direction of the magnetic field is reversed.
• "The Motor Effect" is used in many different devices.
• The speed of the motor can be increased by increasing the size of the current.
• The direction of the motor can be reversed by receeding the direction of the curent.
• When a current passes through the coil, the coil spins because:

 - the force acts on each side of the coil due to "The Motor Effect".

 - The force on one side of the coil is in the opposite direction to the force on the other side.

• Because the sides swap over each half-turn, the coil always spins in the same direction.