Q. 21

A barometer is constructed with its tube having radius 1.0 mm Assume that the surface of mercury in the tube is spherical in shape. if the atmospheric pressure is equal to 76 cm of mercury, what will be the height raised in the barometer tube? The contact angle of mercury with glass = 135° and surface tension of mercury = 0.465 N m-1. Density of mercury 13600 kg m-3.

Answer :

75.5 cm

Given, radius of capillary,


surface tension of mercury,


Contact angle,


Density of mercury,


Length in mercury column of atmospheric pressure,


Due to surface tension, there is a capillary rise seen in the tube.


The rise of mercury column,



The negative sign is used as mercury goes down in a capillary tube.


The height of mercury in the tube thus becomes,


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Fluid Statics67 mins
Wave mechanical model of atom66 mins
Viscosity | World of Fluids51 mins
Laws of states of matter44 mins
Elasticity52 mins
Interactive quiz on liquefaction44 mins
Liquefaction of gases53 mins
Gaseous state- interactive quiz56 mins
Interactive quiz on Kinetic Theory and Real Gas equation52 mins
Interactive Quiz on Mole concept - 264 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses
RELATED QUESTIONS :

For a surface molecule

Physics - Exemplar