Which statement best describes the function of an interlock in a control circuit?

• A. It prevents two incompatible operations from occurring in sequence, physically preventing engagement when the other is active.
• B. It speeds up operation by bypassing safety interlocks.
• C. It reduces circuit current.
• D. It stores energy for later use.

Answer: (A)

An interlock is a safety feature in a control circuit that prevents incompatible actions from happening at the same time by blocking the second operation when the first is already active. It either physically prevents engagement or interrupts the electrical path so the opposing action cannot energize. This keeps the machine in a safe, proper sequence and helps avoid damage or injury. It isn’t about speeding up operation, reducing current, or storing energy.