What is the third listed advantage of AC motors over DC motors?

• A. A readily available power supply
• B. Cheaper
• C. Maintenance Cost
• D. Less Weight

Answer: (C)

The key idea here is that AC motors tend to require far less ongoing maintenance than DC motors. Most AC motors, especially induction types, have no carbon brushes or commutator. Those components are the parts that wear out in DC motors and need regular inspection, replacement, and servicing. With fewer wear-prone parts, the routine maintenance tasks are simpler and less frequent, which translates to lower maintenance costs over the motor’s life. Bearings and lubrication are still part of maintenance, but they’re standard and less workload-intensive than maintaining brushes and a commutator. That combination is why maintenance cost is listed as the advantage for AC motors. The other options aren’t as tied to maintenance: power supply availability can apply to both motor types, weight can vary by design, and upfront cost isn’t a guaranteed advantage of AC motors.