NCERT Class 11 Physics Solutions: Chapter 10 – Mechanical Properties of Fluids-Part 4 (For CBSE, ICSE, IAS, NET, NRA 2023)

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Question 10.6:

Torricelli՚s barometer used mercury. Pascal duplicated it using French wine of density Determine the height of the wine column for normal atmospheric pressure.



Density of mercury,

Height of the mercury column,

Density of French wine,

Height of the French wine column

Acceleration due to gravity,

The pressure in both the columns is equal, i.e.. ,

Pressure in the mercury column Pressure in the French wine column

Question 10.7:

A vertical off-shore structure is built to withstand a maximum stress of . Is the structure suitable for putting up on top of an oil well in the ocean? Take the depth of the ocean to be roughly , and ignore ocean currents.

Answer: Yes


The maximum allowable stress for the structure,

Depth of the ocean,

Density of water,

Acceleration due to gravity,

The pressure exerted because of the seawater at depth,

The maximum allowable stress for the structure is greater than the pressure of the sea water The pressure exerted by the ocean is less than the pressure that the structure can withstand. Hence, the structure is suitable for putting up on top of an oil well in the ocean.

Question 10.8:

A hydraulic automobile lift is designed to lift cars with a maximum mass of . The area of cross-section of the piston carrying the load is . What maximum pressure would the smaller piston have to bear?


The maximum mass of a car that can be lifted,

Area of cross2section of the load2carrying piston,

The maximum force exerted by the load,

The maximum pressure exerted on the load-carrying piston,

Pressure is transmitted equally in all directions in a liquid. Therefore, the maximum pressure that the smaller piston would have to bear is .