Answer:
Amplitude
Step-by-step explanation:
A ripple tank is a tank of liquid (mostly water) which is used to observe the behaviour of the propagation of wave. It is commonly used to describe the principles involved in the reflection, refraction and diffraction of waves.
The tank is filled at its bottom with liquid. A bar is located at one of its ends and this bar is connected to an electric motor which causes a vertical motion of the bar. When the frequency of the electric motor is changed, there is a corresponding change in the speed, amplitude and position of the oscillator. Two common controls of the ripple tank are;
i. the frequency control.
ii. the amplitude control.
For two dimensional waves, these controls are called Frequency and Amplitude respectively.