For a lever, if the effort arm is twice as long as the load arm, what is the mechanical advantage (ignoring friction)?

• A. 1
• B. 0.5
• C. 2
• D. 4

Answer: (C)

When a lever is used, the turning effect (torque) comes from multiplying a force by its distance from the fulcrum. In an ideal lever, the effort torque equals the load torque, so the mechanical advantage equals the ratio of the effort arm length to the load arm length. If the effort arm is twice as long as the load arm, that ratio is 2, giving a mechanical advantage of 2. That means the load force is twice the effort force (ignoring friction).