In a belt drive, power transmission is primarily achieved through which mechanism?

• A. FrictIon between belt and grooves
• B. Teeth engagement to prevent slip
• C. Magnetic attraction
• D. Hydraulic pressure

Answer: (B)

A belt drive can transmit power with a positive, non-slip engagement when the belt has teeth that mesh with matching grooves on the pulley. This tooth engagement locks the belt to the pulley so rotation is synchronized and slip is prevented, allowing reliable torque transfer even under higher loads. In contrast, plain belt drives rely mainly on friction between smooth belt surfaces and the pulley, which can slip if the load is high or if there’s misalignment. Magnetic attraction and hydraulic pressure don’t play a role in standard belt drives. So the teeth gripping the pulley to provide a positive drive is the mechanism that actually ensures power is transmitted without slip.