Electric Motor

Electric Motor converts electrical elnergy to

• mechanical energy
• chemical energy
• thermal energy
• nuclear energy

Which appliances use electric motor?

• Toasters
• Microwaves,

• Washing machines, refrigerators, vacuum cleaners, fans, and blenders.
• Electric kettles

What is the working principle of an electric motor?

• An electric motor generates electricity from mechanical energy.
• An electric motor uses only thermal energy to operate.
• An electric motor relies on chemical reactions to produce motion.
• An electric motor converts electrical energy into mechanical energy using the interaction of magnetic fields and electric currents.

What is the function of a commutator in an electric motor?

• The commutator increases voltage to the motor.
• The commutator acts as a power source for the motor.
• The commutator cools down the motor during operation.
• The commutator reverses current direction to maintain consistent torque in an electric motor.

What is the purpose of reversing current in an electric motor?

• To improve the motor's efficiency.
• To ensure continuous rotation of the coil in one direction

• To reduce energy consumption.
• To increase the motor's speed.

Describe the role of the soft-iron cylinder in a motor.

• The soft-iron cylinder enhances the magnetic field and improves motor efficiency.
• The soft-iron cylinder acts as a heat sink to cool the motor components.
• The soft-iron cylinder reduces the magnetic field and decreases motor efficiency.
• The soft-iron cylinder is used to store electrical energy for later use.

Evaluate how increasing current flow might impact the motor’s energy efficiency and performance.

• Increasing current flow has no effect on performance.
• Higher current flow always improves energy efficiency.
• Increasing current flow can enhance performance but may reduce energy efficiency due to increased heat losses.
• Reducing current flow increases heat losses.

If you increase the number of turns in a coil, what change would you observe in a motor’s performance?

• The motor's performance improves due to increased torque.
• The motor's performance improves but only at high speeds.
• The motor's performance remains unchanged regardless of the number of turns.
• The motor's performance decreases due to reduced torque.

Why does the split-ring commutator reverse the current direction at each half-turn?

• It allows the motor to change its rotational direction randomly.
• The split-ring commutator reverses the current direction at each half-turn to ensure continuous rotation of the motor.
• It increases the speed of the motor at each half-turn.
• It prevents the motor from rotating continuously.