Applications of Atmospheric Pressure

Question 1What type of pressure is involved in the filling of a liquid in a syringe?

Question 2 What is a rubber sucker?

Question 3 How does a rubber sucker works?

Question 4 State few uses of rubber sucker?

Question 5 How does a syringe work?

Question 6 What is a syringe?

Question 7 How does a dropper work?

Question 8 What is a dropper?

(1) Drinking Straw

The drinking straw is a very thin pipe which is used to drink Soft drinks. The drinking straw works on the existence of atmospheric pressure. The lower end of drinking straw is dipped in the soft drink. When we suck at the upper end of the straw with our mouth, the pressure of air inside the straw and in our inner mouth is reduced. But the pressure acting on the surface of soft drink is equal to the atmospheric pressure. Greater atmospheric pressure acting on the surface of the soft drink pushes the soft drink up the straw into our mouth.

(2) Syringe

A glass tube with a nozzle and Piston for sucking in and ejecting liquid in a thin stream is called syringe. The syringe works on the existence of atmospheric pressure. When the nozzle of a syringe is dipped in a liquid and its piston is withdrawn, the pressure inside the syringe is lower. The greater atmospheric pressure acting on the surface of the liquid pushes the liquid up into the syringe.

(3) Dropper

The dropper is a short glass tube with a rubber bulb at one end and a nozzle at the other end. When we press the rubber bulb of the dropper by keeping its nozzle dipped in the liquid, air present in the glass tube and bulb is seen to escape in the form of bubbles. Due to this, air pressure inside the glass tube and rubber bulb of dropper is very much reduced. When we now release the rubber bulb of dropper, the much greater atmospheric pressure acting on the surface, pushes the liquid up into the dropper tube. The rise of liquid in a dropper is due to  atmospheric pressure .If we remove the filled dropper from the container of liquid and press its rubber bulb slowly then the drops of liquid will come out of the nozzle of dropper tube.

(4) Rubber sucker

A rubber sucker is a device made of rubber that sticks firmly to flat and smooth surfaces on pressing. A rubber sucker looks like a small, concave – shaped rubber cup. A rubber sucker is also called a suction Cup because it sticks to a surface by suction. When we press the rubber sucker on a flat, smooth, surface, its concave rubber cup gets flattened to a large extent, pushing out most of the air from beneath it. Since very little air remains inside the flattened rubber sucker, therefore the air pressure inside the rubber sucker becomes very low. The much greater atmospheric pressure acting on the rubber sucker from outside fixes the rubber sucker firmly to a flat surface due to the atmospheric pressure.

(1) Rubber suckers are usually used to hold objects together with the help of suction.

(2) They are used to hold glass table tops on to the wooden frames of table.

(3) They are used for making suction hooks fixed on walls, doors and almirahs.

A suction hook is a rubber sucker having a plastic hook attached to it.