A coupling provides a way of transmitting torque and speed from one shaft to another.

• A. Torque and Speed
• B. Power and Voltage
• C. Force and Acceleration
• D. Current and Resistance

Answer: (A)

A coupling’s job is to transfer rotational motion from one shaft to another, including the twisting force that drives the shaft (torque) and the rate at which the shaft turns (speed). These two quantities describe the mechanical work being conveyed between shafts. Power is related to them (power = torque × speed) but is a derived result, not a separate quantity the coupling passes. Electrical properties like voltage, current, and resistance aren’t involved in the mechanical transmission, and while forces and accelerations describe motion, a coupling specifically transmits torque and rotational speed. So torque and speed best describe what a coupling conveys between shafts.