Load characteristics of DC motors, losses and efficiency in DC m

What are the two main components of the armature and field circuit in a DC motor?

• Armature and Field Circuit

• Shaft and Gear

• Rotor and Stator

• Battery and Switch

Explain the function of brushes in a DC motor.

• To cool down the motor

• To transfer electrical power to the rotating armature

• To provide support for the motor casing

• To generate electricity for the motor

What are the differences between brush and brushless DC motors?

• Type of the motor

• Size of the motor

• Color of the motor

• Presence of brushes

How does copper loss occur in a DC motor?

• Because of the high efficiency of the copper windings in the armature and field coils.

• Due to the resistance of the copper windings in the armature and field coils.

• Due to the presence of aluminum windings in the armature and field coils.

• As a result of the low resistance of the copper windings in the armature and field coils.

What is the significance of iron losses in a DC motor?

• Decrease in motor efficiency

• Significant impact on motor efficiency and heating

• Increase in motor speed

• No impact on motor performance

How is efficiency calculated in a DC machine?

• Output power divided by input power

• Voltage multiplied by current

• Efficiency is not calculated in a DC machine

• Input power divided by output power

Explain the speed-torque characteristics of a DC motor.

• The speed-torque characteristics of a DC motor show the relationship between the motor's weight and the torque it produces.

• The speed-torque characteristics of a DC motor show the relationship between the motor's size and the torque it produces.

• The speed-torque characteristics of a DC motor show the relationship between the motor's speed and the torque it produces.

• The speed-torque characteristics of a DC motor show the relationship between the motor's color and the torque it produces.

What factors affect the speed-torque characteristics of a DC motor?

• Temperature of the surrounding environment

• Color of the motor casing

• Supply voltage, armature resistance, and magnetic field strength

• Number of screws in the motor