Page 163 - Physics

Pressure

carries more weight of the liquid. Then, Applications of siphon
the force of gravity draws the liquid Siphon is applied in many areas and
through the long arm and this maintains devices that are used every day.
the low pressure that is established at 1. It is used in the toilet fl ushing systems
the start. Once started, the siphon does (chain and ball tank). The fl ush is
not require additional energy to maintain triggered by a handle that operates a
liquid fl ow out of the reservoir. The siphon simple diaphragm like piston pump
will pull the liquid out until the level in that lifts enough water. The same
the reservoir falls below the intake point. procedure is used in the automatic
fl ushing tank, which does not require
Acti vity 7.7 a handle to trigger the fl ushing.

Aim: To demonstrate the 2. It is used to drain excess water in
principle of the siphon. special rain gauges called siphon rain
gauges.
Materials: Rubber tube, water and
two empty cans 3. A siphon cup is a reservoir attached
Procedure to a spray gun.
1. Pour water into can 1 up to about 4. It is used to drain water in some
halfway and set it on the edge of a drainage systems.
table.
2. Set an empty can 2 on the fl oor Task 7.5
underneath can 1 on the table. Discuss the application of siphon in
3. Take a piece of rubber tubing that is the automatic fl ushing tank and toilet
long enough to reach both cans and fl ushing system. Discuss other areas
fi ll it with water. where the siphon is applied.

4. Cover both ends of the tube with
your fi ngers (you may need a partner Vacuum cleaner
to do this). A vacuum cleaner shown in Figure 7.33
5. Immerse one end of the tube into the is used in cleaning fl oors and carpets.
can with water and the other end into It also utilizes the atmospheric pressure
the empty can. to work. When it is on, the fan inside

6. Uncover both ends of the tube and the cylinder blows air out as a result, a
observe what happens. partial vacuum is created inside. This
makes the atmospheric pressure outside
Question the cylinder higher; hence forcing air and
Does the water fl ow from one can to dust particles into the cleaner.
the other? Explain.

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