Doppler effect

Equipment :
• Ultra sonic receiver with holder
• Ultra sonic transmitter with holder
• Function generator 40KHz
• AC amplifier
• Oscilloscope
• Digital frequency counter.
• Car with motor with variable speed.
• Trolley for car.
• Power supply for motor.
• Connection Cables


• In the experiment two identical ultrasonic transducers are used as the transmitter and the receiver, and differ only in their connection.
• One transducer is mounted on a measuring trolley with electric drive, while the other transducer is at rest on the lab bench. The frequency of the received signal is measured using a high-resolution digital counter.
• To determine the speed of the transducer in motion, the time Δt which the measuring trolley requires to traverse the measuring distance is measured using a stop watch