Mechanical Properties of Fluids

The compressibility of water is 6x 10² N^-1m². If one litre is subjected to a pressure of 4 x10⁷ Nm^-2, the decrease in its volume is

• 2.4 cc

• 10 cc

• 24 cc

• 15 cc

Bernoulli's principle is not involved in the working/explanation of

• movement of spinning ball

• carburettes of automobile

• blades of a kitchen mixer

• heart attack

The onset of turbulence in a liquid is determined by

• Pascal's law

• Magnus effect

• Reynold's number

• Bernoulli's principle

n identical drops, each of capacitance C and charged to a potential V, coalesce to form a bigger drop. Then the ratio of the energy stored in the big drop to that in each small drop is

• n^5/3 : 1

• n^4/3 : 1

• n : 1

• n³ : 1

A small spherical ball falling through a viscous medium of negligible density has terminal velocity v. Another ball of the same mass but of radius twice that of the earlier falling through the same viscous medium will have terminal velocity

• v

• v/4

• v/2

• 2v

The excess pressure inside a spherical drop of water is four times that of another drop. Then their respective mass ratio is

• 1 : 16

• 8 : 1

• 1 : 4

• 1 : 64

In a capillary rise experiment, the water level rises to a height of 5 cm. If the same capillary tube is placed in water such that only 3 cm of the tube projects outside the water level, then

• water will begin to overflow through the capillary

• angle of contact decreases

• angle of contact increases

• the meniscus completely vanishes

Eight drops of a liquid of density ρ and each of radius a are falling through air with a constant velocity 3. 75 cms^-1. When the eight drops coalesce to form a single drop the terminal velocity of the new drop will be

• 1.5 × 10^-2 ms^-1

• 2.4 × 10^-2 ms^-1

• 15 × 10^-2 ms^-1

• 25 × 10^-2 ms^-1

The excess pressure inside one soap bubble is three times that inside a second soap bubble, then the ratio of their surface areas is

• 1 : 9

• 1 : 3

• 3 : 1

• 1 : 27

The area of cross-section of one limb of an U-tube is twice that of other. Both the limbs contain mercury at the same level. Water is poured in the wider tube so that mercury level in it goes down by 1 cm. The height of water column is (density of water = 10³ kg m^-3, density of mercury = 13.6 x 10³ kg m^-3)

• 13.6 m

• 40.8 m

• 27.2 m

• 54.4 m