Ripple Tank
The Ripple
Tank provides a visual method of showing wave
diffraction and interference. The tank may be placed upon an
overhead
projector.
To show a single plane wave, the tank is lifted and
rapidly
dropped.
The screen shows the plane wave.
Then placing a block on the
tank glass
as a barrier, the plane wave may be used to show diffraction
around a barrier.
The adjustable
phase wave generator may be used to generate both
plane waves and two in-phase waves. Two batteries and a decade
resistor
box provide speed control for the adjustable phase
wave generator.
Attach the
long board to the rider extension and insert in the rider.
Then using
the wooden barrier, diffraction may be shown again. This
then leads
to the interference of waves created by a single plane wave
that impinges on two openings between
barriers. Finally, place
the
dipper with the two dabbers on the glass. Adjust the dabbers to get
the
maximum observable wave. Turn on the wave generator and point out
the
places of positive and negative
interference.