What is the correct description of DC motors?

What is the correct description of DC motors?

• A. They run on direct current where electrical charge flows in one direction
• B. They run on alternating current where current periodically changes direction
• C. They operate only with AC supply
• D. They store energy magnetically and do not move current

Answer: (A)

Direct current motors are designed to convert electrical energy from a direct current source into rotational mechanical energy, with the electricity flowing in one direction. That steady, unidirectional current creates a magnetic interaction that produces torque, and in brushed DC motors a commutator keeps the torque in the same rotational direction as the rotor turns. This fits the description that a DC motor runs on direct current where the charge flows in one direction. In contrast, the idea of alternating current describes AC motors, which rely on current that periodically reverses direction to generate motion. The notion that DC motors operate only with AC supply is not accurate, and the idea that they store energy magnetically to prevent current flow is not how motors operate—the magnetic fields come from magnets and windings, while energy is drawn from the electrical supply to drive motion.

Direct current motors are designed to convert electrical energy from a direct current source into rotational mechanical energy, with the electricity flowing in one direction. That steady, unidirectional current creates a magnetic interaction that produces torque, and in brushed DC motors a commutator keeps the torque in the same rotational direction as the rotor turns.

This fits the description that a DC motor runs on direct current where the charge flows in one direction. In contrast, the idea of alternating current describes AC motors, which rely on current that periodically reverses direction to generate motion. The notion that DC motors operate only with AC supply is not accurate, and the idea that they store energy magnetically to prevent current flow is not how motors operate—the magnetic fields come from magnets and windings, while energy is drawn from the electrical supply to drive motion.