Siphon with pump
The word siphon is also spelled siphon ,is sometimes used to refer to a wide variety of devices that involve the flow of liquids through tubes but in the narrower sense it refers specifically to a tube in an inverted U shape which causes a liquid to flow uphill,above the surface of the reservoir , without pumps ,powered by the fall of the liquid as it flows down the tube under the pull of gravity ,water is discharged at a level lower than the surface of the reservoir .Note that while the siphon must touch the liquid in the (upper) reservoir.(the surface of the liquid must be above the intake opening ),it need not touch the liquid in the lower reservoir and indeed there need not be a lower reservoir -liquid in the lower reservoir-liquid can discharge into mid-air.
A siphon works because gravity pulling down on the taller column of liquid causes reduced pressure at the top of the siphon also called hydrostatic pressure.This reduced pressure means gravity pulling down on the shorter column of liquid is not sufficient to keep the liquid stationary so it flows from the upper reservoir up and over the top of the siphon.
,Two small buckets
.Rubber pipe (atleast one meter long)
.Small cards to label the buckets i.e A,B
1.Take consent of the child and introduce the name of the experiment and explain its purpose.
2.Put one bucket (A) at ground level and other bucket (B) at higher level and paste tags of A and B respectively on buckets .
3.Pour water in bucket (B) and fill it atleast a little more than half.
4.Dip one end of pipe in bucket (B) and suck from the other end of pipe a little and dip this end of the pipe in bucket(A).
5.Observe the transfer of water from bucket (B) to bucket (A) .
You will observe that of all water is transferred to bucket (A)
6.Then tell the child that this pipe/tube through which water is transferred in this way is called siphon.