A timing or gear belt will not slip due to the ______ engagement between the teeth and notches of the belt and pulley.

• A. Negative
• B. Friction
• C. Positive
• D. Magnetic

Answer: (C)

Positive engagement means the belt’s teeth fit into matching grooves on the pulley, creating a rigid, interlocked connection. Because the teeth physically mesh with the notches, motion is transmitted directly without relying on surface friction, so the belt and pulley rotate as one unit and stay in sync. This prevents slip under normal operating loads, which is crucial for timing belts that must maintain precise timing. If the drive depended on friction, belt stretch or load spikes could cause slip and timing errors. Magnetic engagement isn’t applicable here, and negative engagement isn’t a standard mechanism for this type of drive.