Which type of connection completes the list for a clutch: mechanical, magnetic, hydraulic, pneumatic, or ______?

Which type of connection completes the list for a clutch: mechanical, magnetic, hydraulic, pneumatic, or ______?

• A. Mechanical
• B. Magnetic
• C. Hydraulic
• D. Friction

Answer: (D)

The concept being tested is the different ways a clutch can transfer torque. Mechanical, magnetic, hydraulic, and pneumatic describe how the clutch is actuated or engaged, but the method by which torque is actually transmitted between the mating surfaces is through friction. A friction clutch uses friction between two surfaces (with friction materials) that are pressed together to transmit torque. This friction-based engagement is a classic and distinct category from the others, so the missing type is friction.

The concept being tested is the different ways a clutch can transfer torque. Mechanical, magnetic, hydraulic, and pneumatic describe how the clutch is actuated or engaged, but the method by which torque is actually transmitted between the mating surfaces is through friction. A friction clutch uses friction between two surfaces (with friction materials) that are pressed together to transmit torque. This friction-based engagement is a classic and distinct category from the others, so the missing type is friction.