CONSTRUCTION AND TEST OF DEMONSTRATION APPARATUS FOR INTERFERENCE-DIFFRACTION LEARNING USING ON-AIR ULTRASONIC WAVE

• Main Author: PURNOMO (NIM: 20207059), ARIS
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/11870
• Institution: Institut Teknologi Bandung

Laboratory equipment for quantitative sound wave interference-diffraction learning is hardly available. Generally this kind of apparatus is not provided at schools. For improving students' cognitive, affective and psychomotor competences on balance, some learning models based on experiments are required. Hence, Physics teachers' creativity is needed to visualize Physics phenomena from its effect either directly or indirectly. This creativity could appear as constructing or designing demonstration apparatus or laboratory equipment. Interference and diffraction concepts are needed in constructing demonstration apparatus for on-air ultrasonic wave interference-diffraction learning. Frequency was calculated based on the measured wave length which was obtained with measuring the difference of wave-path from slit to maximum and minimum patterns on screen. These maximum and minimum patterns were received by a receiver completed with sound and voltmeter to measure the signal emerged due to waves from transmitter. The research result shows that this designed apparatus can be used to demonstrate the wave interference-diffraction patterns indirectly and to measure ultrasonic wave frequency on air. The measurement held at Physics laboratory ITB with room temperature of 25 oC yielded mean-frequency of 40480 Hz with mean-uncertainty of 3,89%.