A tachometer measures which parameter of a rotating machine?

A tachometer measures which parameter of a rotating machine?

• A. Speed
• B. Voltage
• C. Current
• D. Torque

Answer: (A)

A tachometer measures how fast a rotating shaft is turning, typically in revolutions per minute (rpm). It provides the speed of rotation, not electrical values or twisting force. Voltage and current are electrical properties, not mechanical speed, and torque is the twisting force on the shaft. So the tachometer’s reading is all about rotational speed.

A tachometer measures how fast a rotating shaft is turning, typically in revolutions per minute (rpm). It provides the speed of rotation, not electrical values or twisting force. Voltage and current are electrical properties, not mechanical speed, and torque is the twisting force on the shaft. So the tachometer’s reading is all about rotational speed.