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.