# Ripple Tank

Show/Hide Sub-topics (General Wave Properties | O Level)

The ripple tank is used to generate water waves in laboratory. It is useful in demonstrating wave properties such as reflection and refraction. It consists of a shallow tray of water with a transparent base, a light source directly above the tray and a white screen beneath the tray to capture the image of the shadows formed when water waves spread across the tank as shown above. Straight waves can be set up by using a straight dipper, while circular waves can be formed by using a spherical dipper. Both dipper are vibrated up and down by a motor.

The waves will be seen in bright and dark patches on the screen below the tray. These patches show the position of the crests and troughs of the waves. The dark patches will correspond to the crests and bright patches will be the troughs.

Why does the dark patches correspond to the crests and bright patches correspond to the troughs?

Click to show/hide answer
Light is absorbed/scattered as it passes through a body of water. At a crest, the light has to travel a longer distance through the water, which will cause more light to be absorbed/scattered. This will cause crests to appear as dark patches. The opposite logic applies to the troughs. At a trough, the light travels a shorter distance through the water, which causes less light to be absorbed/scattered. This causes troughs to appear as bright patches.

Video of a ripple tank in action

### 20 thoughts on “Ripple Tank”

1. I can’t understand about this topic plz help me
😔

2. What about reflection and refraction

3. Can the dark and bright lines appear on the screen be in other colour…? If no then why?
Pls help

4. How can the waves in ripple tank be made to travel more slowly and when this happen,what will be its effect on frequecny and wavelenght of the waves?

5. there is any project of ripl tank??????

• Your answer in in the post

6. i have make riple tank project and it is in working now

7. this mini physics really helped me for my test which was based on waves

8. I am new here but from what I see from mini physics it can help me to build up in physics.

9. While studying waves in ripple tank,crest of the wave appear as bright line and trugh appear as black portion .why .Give reason plz

• This question is answered in the post.

• If the light is other than white colour then what type of lines will appear on the screen?
Pls help

10. Mini physics is the best
It is helping me a lot
Its easy to understand
Keep up with the good work because its very helpful

11. How can a transverse wave be shown in a ripple tank?

• Water wave is a transverse wave. The ripple tank shows the crests and trough of the water wave.

• The crests act as converging lenses that focus light,producing the bright lines. The troughs act as diverging lenses that scatter light, producing the dark lines. You have written it the other way round. Otherwise, the information was very helpful.