Which regulator is more prone to wear due to moving parts?

• A. Carbon pile regulator
• B. Vibrating points regulator
• C. Solid-state regulator
• D. Electronic regulator

Answer: (B)

Moving parts wear out fastest when they are repeatedly switching under load. The vibrating points regulator uses a pair of electrical contacts that continually open and close (vibrate) to regulate output. This rapid switching causes arcing and mechanical rubbing at the contact surfaces, leading to noticeable wear over time. The other types rely on methods that don't involve frequent contact making/breaking: carbon pile regulators adjust resistance via the carbon stack without continuous contact switching, and solid-state/electronic regulators use no moving electrical contacts at all, so they avoid wear from switching altogether (their wear comes mainly from thermal effects and aging).