A Magnetic reversing starter consists of a starter and a set of contactors with electrical and mechanical interlocking preventing the _____ of both units from being energized at the same time.

• A. Coil
• B. Contacts
• C. Armature
• D. Power supply

Answer: (B)

The key idea is that reversing starters use interlocking to prevent both directions from being energized at the same time. The interlock acts to stop the coils of the forward and reverse contactors from being energized simultaneously, so only one coil can pull in at a time. This is essential because energizing both coils could cause conflicting connections through the motor leads or damage the control circuit. The part that is actually energized to make the contacts operate is the coil of a contactor, not the contacts themselves. The term “armature” refers to a moving part inside a device, not what’s being energized in this context, and the power supply isn’t what the interlock prevents from energizing—it's the coils.