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Following statements are given for DC motors (a) DC motors require less maintenance than AC motors (b) DC motors cannot provide high starting torque (c) DC motors are not suitable for very high-speed applications (d) The methods of speed control of DC motors are simpler and less expensive than those of AC motors Which of the following statements are correct?

Following statements are given for DC motors (a) DC motors require less maintenance than AC motors (b) DC motors cannot provide high starting torque (c) DC motors are not suitable for very high-speed applications (d) The methods of speed control of DC motors are simpler and less expensive than those of AC motors Which of the following statements are correct? Correct Answer (c) and (d)

BASICS

AC MOTOR

DC MOTOR

Nature of the Input Current

Alternating Current is the main input power in the AC motor

Direct Current is the main input power in the DC motor

Supply Phase

Both single-phase and three-phase supply are used

Only single-phase supply is used

Number of terminals

There are 3 input terminals RYB

There are two input terminals: Positive and Negative

Carbon Brushes

Absent

Two carbon brushes

Applications

Suitable for large ad industrial applications

Used in small and domestic applications

Starting

Not Self starting. It requires some external starting equipments

DC motors are self-starting

Maintenance Cost

Less Expensive as compared to DC Motor

DC motor maintenance is more expensive

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