What is a key feature of a universal motor?

What is a key feature of a universal motor?

• A. Low efficiency per weight
• B. High power output per pound of weight
• C. Reliance on AC power only
• D. Limited speed control

Answer: (B)

A universal motor is characterized by its ability to operate efficiently on both alternating current (AC) and direct current (DC). One of its standout features is the high power output it can deliver relative to its weight. This means that for applications where weight is a critical factor—such as in portable power tools—the universal motor provides a significant advantage, allowing for strong performance without adding excessive bulk. The design of universal motors typically incorporates components that enable high speeds and robust power generation, leading to efficient operation in demanding tasks. This makes them particularly suitable for devices like vacuum cleaners and electric shavers, where both power and compactness are essential. In contrast, other aspects, such as low efficiency per weight, reliance solely on AC power, and limited speed control, do not apply to universal motors, thereby highlighting why the feature of high power output per pound of weight is a defining characteristic.

A universal motor is characterized by its ability to operate efficiently on both alternating current (AC) and direct current (DC). One of its standout features is the high power output it can deliver relative to its weight. This means that for applications where weight is a critical factor—such as in portable power tools—the universal motor provides a significant advantage, allowing for strong performance without adding excessive bulk.

The design of universal motors typically incorporates components that enable high speeds and robust power generation, leading to efficient operation in demanding tasks. This makes them particularly suitable for devices like vacuum cleaners and electric shavers, where both power and compactness are essential.

In contrast, other aspects, such as low efficiency per weight, reliance solely on AC power, and limited speed control, do not apply to universal motors, thereby highlighting why the feature of high power output per pound of weight is a defining characteristic.