- Magnet – to produce magnetic field (B)
- Coil ABCD – placed in B
- External circuit
- Battery – to power the circuit and coil
- Key – to switch on/off the current in the circuit
- Axle – supports the split rings, rotates the coil in the magnetic field, B
- Stationary Carbon brushes (B1, B2) – connects the coil to the external circuit
- Two Split rings (R1, R2) – outer side conducting, inner side insulated to prevent the current passing through the axle.
Working
- Key is closed to pass the current through the circuit.
- Brushes connect the circuit to the split rings.
- Current is passed through the coil.
- When current passes from A to B through coil in presence of the magnetic field lines emerging from North pole to South pole, an upward force is created. (Fleming’s left hand rule)
- NOTE: B, I and F are mutually perpendicular to one another.
- When current passes from B to C in the coil, it is parallel to the magnetic field lines. Hence no force is experienced.
- When current passes from C to D in the coil, which is perpendicular to the direction of magnetic field, B, downward force is experienced.
- These opposite forces cause a clockwise rotation.
- When the direction of current is reversed, the rotation of the coil is anticlockwise.
- With the continuous feeding of current in one direction, electrical energy is converted into a mechanical energy.