What is an advantage of solid-state control in electrical systems?

• A. It has no moving parts.
• B. It uses mechanical relays that wear out.
• C. It requires frequent lubrication.
• D. It generates significant arcing during switching.

Answer: (A)

Solid-state control uses semiconductor devices to switch circuits, so there are no physical contacts that move. Because nothing is rubbing or opening and closing like a relay, there’s no wear on contacts, no lubrication needed, and switching happens with minimal arcing. This combination leads to higher reliability and longer service life, especially in frequent or rapid switching applications.

That’s why the advantage is the absence of moving parts. The other options describe characteristics of mechanical relays—wear from contacts, need for lubrication, and arcing from bouncing contacts—which aren’t present in solid-state controls.