When we press the bulb of a dropper with its nozzle kept in water, air in

the dropper is seen to escape in the form of bubbles. Once we release the

pressure on the bulb, water gets filled in the dropper. The rise of water in

the dropper is due to

(a) pressure of water

(b) gravity of the earth

(c) shape of rubber bulb

(d) atmospheric pressure

Answer

(d) atmospheric pressure.



Water rises in the dropper due to atmospheric pressure.

When bulb is pressed, air present in tube and bulb escapes in the form of bubbles.

Due to this, Pressure inside bulb decreases

However, there is atmospheric pressure on surface of liquid.

When we release the bulb, the water moves inside the tube.

Water moves from higher pressure (from water kept) to lower pressure (inside the glass tube).

 

  1. Class 8
  2. Chapter 11 Class 8 - Force And Pressure

About the Author

CA Maninder Singh's photo - Expert in Practical Accounts, Taxation and Efiling
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 9 years and a teacher from the past 16 years. He teaches Spoken English, Written English, Grammar and Vocabulary at Englishtan.