Two capillary tubes of different diameters are dipped in water. The rise of water is

• the same in both tubes

• greater in the tube of larger diameter

• greater in the tube of smaller diameter

• independent of the diameter of the tube

Mille is an example for

• emulsion

• inelastic gel

• foam

• elastic gel

Spheres of iron and lead having same mass are completely immersed in water. Density of lead is more than that of iron. Apparent loss of weight is w₁ for iron sphere and w₂ for lead sphere, Then $\frac{{\mathrm{w}}_1}{{\mathrm{w}}_2}$ is

• > 1

• = 1

• become 0 and 1

• = 0

Two solds P and Q float in water. It is observed that P floats with half of its volume immersed and Q floats with $\frac{2}{3}$rd of its volume is immersed. The ratio of densities of P and Q is

• $\frac{4}{3}$

• $\frac{3}{4}$

• $\frac{2}{3}$

• $\frac{3}{2}$

A flow of liquid is streamline, if the Reynold's number is

• less than 1000

• greater than 1000

• between 2000 to 3000

• between 4000 to 5000

An ideal fluid flows through a pipe of circular cross-section with diameters 5 cm and 10 cm as shown in the figure. The ratio of velocities of fluid at A and B is

• 4 : 1

• 1 : 4

• 2 : 1

• 1 : 2

'Hydraulic lift' works on the basis of

• Stoke's Law

• Bernoulli's Law

• Pascal's Law

• Toricelli's Law

Two non-mixing liquids of densities  and n (n >1) are put in a container. The height of each liquid is h. a solid cylinder of length L and density d is put in this container. The cylinder floats with its axis vertical and length pL (p<1) in the denser liquid. The density d is equal to,

• 
• 

• {1+(n-1)p}

• {1+(n-1)p}

The wind with speed 40 m/s blows parallel to the roof of a house. The area of the roof is 250m². Assuming that the pressure inside the house is atmospheric pressure, the force exerted by the wind on the roof and the direction of the force will be( p_air = 1.2 kg/m³)

• 4.8 x 10⁵ N, downwards

• 4.8 x10⁵ N , upwards

• 2.4 x 10⁵ N , upwards

• 2.4 x 10⁵ N , upwards

80.

A certain number of spherical drops of a liquid of radius r coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid, then

• Energy = 4VT  is released.

• Energy = 3VT is absorbed

• Energy = 3 VT  is released

• Energy is neither absorbed nor released.