Velocity of sound inliquid by Laser

Equipment:

• Laser Diode with power supply.
• Lens with holder.
• Optical bench 90cm.
• Water bath.
• Ultrasonic speaker.
• Function Generator.
• Screen.

Description

• A stationary ultrasonic wave in a glass cell full of liquid is traversed by a divergent beam of light.
• The sound wavelength can be determined from the central projection of the sound field on the basis of the refractive index which canges with the sound pressure.