Based on principle of stationary wave produced due to superposition of incident waves moving toward pulley and reflected waves from pulley towards tuning fork.
A heavy steel fork making about 60 vibrations per second is mounted on heavy cast iron base. The two prongs vibrate due to the electrically maintained magnet, placed between the two prongs. The electromagnet is adjustable so that amplitude of vibrations may be varied.Note: Table is not in scope of supply.