SOLUTION

• Tachogenerator is a device that generates an electrical output directly proportional to the shaft speed.
• The voltage thus generated is fed to a speedometer for speed measurement and/or used as a feedback signal for controlling the speed of a rotating machine/equipment.
• A speedometer or a speed meter is a gauge that measures and displays the instantaneous speed of a vehicle.
• Here the change in speed will be sensed by the speedometer thus speedometer is used as feedback for the variation of the speed of the car.