Compared to a V-belt drive, a chain drive __________.

• A. is more efficient
• B. is less efficient
• C. has the same efficiency
• D. is twice as efficient

Answer: (A)

The key idea is how power is transferred and how this affects slip and losses. A chain drive engages the sprocket teeth directly, so there is positive contact with little to no slipping as load changes. This keeps the power transfer efficient because most of the input energy goes to the load rather than being wasted as slipping or slipping-related heat. A V-belt drive, on the other hand, depends on friction between the belt and pulleys. Under heavy load, misalignment, or wear, the belt can slip, which wastes energy and reduces efficiency. Because of this, a chain drive is typically more efficient than a V-belt drive, especially at higher torques. The other options overstate or misstate the relationship (that it’s less efficient, the same, or twice as efficient) and don’t align with how slip and engagement affect efficiency.