• An electric motor is a device that converts electrical energy into mechanical energy.

• It works on the principle of the force experienced by a current-carrying conductor in a magnetic field.
• Electric motors are used in devices like fans, washing machines, mixers, and many more.

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Principle

An electric motor works on the principle of Fleming’s Left-Hand Rule:

• When a current-carrying conductor is placed in a magnetic field, it experiences a force.
• The direction of the force is determined by Fleming’s Left-Hand Rule:
  • Thumb → Direction of force (motion).
  • Forefinger → Direction of magnetic field.
  • Middle finger → Direction of current.

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Construction of an Electric Motor

The main parts of a DC motor include:

1. Armature: A rectangular coil of insulated copper wire.
2. Magnet: Two strong permanent magnets or electromagnets to create a magnetic field.
3. Commutator: A split ring that reverses the direction of current in the armature.
4. Brushes: Two carbon brushes that maintain contact between the commutator and the external circuit.
5. Battery: Provides the electric current for the motor to work.

Working of an Electric Motor

1. When current flows through the armature (rectangular coil), it produces a magnetic field around the coil.
2. The magnetic field of the coil interacts with the magnetic field of the magnets.
3. According to Fleming’s Left-Hand Rule, a force acts on both sides of the coil in opposite directions, causing the coil to rotate.
4. The commutator ensures that the current direction in the coil reverses after every half rotation.
   • This keeps the coil rotating continuously in the same direction.
5. The mechanical energy generated is used to drive machines.

Diagram of an Electric Motor

Ensure you understand and can label a simple diagram of a DC motor, including:

• Armature
• Commutator
• Brushes
• Battery
• Magnetic field (N and S poles)
• Direction of current and force

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Applications of Electric Motors

Electric motors are widely used in:

• Household appliances: Fans, washing machines, refrigerators, mixers, etc.

• Industries: Machinery, conveyors, and tools.

• Vehicles: Electric cars, trains, and elevators.

• Toys and small devices: Toys, fans, and pumps.

Key Points to Remember

• Energy Conversion: Electrical energy → Mechanical energy.
• Works on the principle of force on a current-carrying conductor in a magnetic field.
• The commutator reverses current to maintain continuous rotation.
• Fleming’s Left-Hand Rule determines the direction of force.

Conclusion

The electric motor is a key invention that plays a major role in our daily lives and industries, using simple physics principles to generate rotational motion.