Red Seal Industrial Electrician Practice Exam

What differentiates DC motors from AC motors?

1. DC motors run on alternating current

2. DC motors run on direct current while AC motors run on alternating current

3. DC motors have lower torque than AC motors

4. DC motors do not require a power source

The correct answer is: DC motors run on direct current while AC motors run on alternating current

The differentiation between DC motors and AC motors primarily lies in the type of electrical current they utilize for operation. DC motors operate using direct current, which means the flow of electrical charge is unidirectional. This type of current is typically supplied by battery sources or DC power supplies. On the other hand, AC motors are designed to run on alternating current, where the flow of electric charge periodically reverses direction. Understanding this distinction is crucial because it affects various performance characteristics of the motors, including their control mechanisms, efficiency, and application usage. For instance, DC motors are often favored for applications requiring precise speed control and torque, whereas AC motors are widely used for applications where consistent speed and efficiency are more critical. This clear understanding of the types of currents not only aids in recognizing their respective operational environments but also influences the choice of motor based on specific application needs.