What does a DC motor convert?

• A. Mechanical energy into electrical energy
• B. Alternating current into direct current
• C. Direct current into mechanical energy
• D. Electrical energy into thermal energy

Answer: (C)

A DC motor is designed specifically to convert electrical energy into mechanical energy. This process takes place as direct current flows through the motor's windings, creating a magnetic field. The interaction between this magnetic field and the permanent magnets (or the field coil, based on motor design) generates a torque that causes the rotor to spin, resulting in mechanical work.

Understanding this principle is crucial for applications in various industries where motors are used to drive machinery, tools, and vehicles. The efficiency and performance of a DC motor are largely dependent on factors such as the design of the motor windings, the strength of the magnetic field, and the input voltage.

The other choices describe processes that do not accurately reflect the function of a DC motor. For example, a DC motor does not convert mechanical energy into electrical energy or perform the conversion of alternating current to direct current; such functions are carried out by generators or rectifiers, respectively. Additionally, while a motor does generate some thermal energy due to resistance and inefficiencies, its primary purpose is not to convert electrical energy into thermal energy.