If work done in increasing the size of a soap film from 10 cm x 6 cm to 10 cm x 11 cm is 2x10^-4 J, then surface tension is

• 2x10^-2 Nm^-1

• 2x10^-4 Nm^-1

• 2x10^-6 Nm^-1

• 2x10^-8 Nm^-1

At which of the following temperatures, the value of surface tension of water is minimum

• 4º C

• 25º C

• 50º C

• 75º C

Work done in splitting a drop of water of 1 mm radius into 64 droplets is (surface tension of water = 72x 10^-3 J/m²)

• 2.0 x 10^-6 J

• 2.7 x 10^-6 J

• 4 x 10^-6 J

• 5.4 x 10^-6 J

A 700 g solid cube having an edge of length 10 cm floats in water. The volume of the cube outside water is :

• 2.4 cm³

• 4.8 cm³

• 300 cm³

• 500 cm³

85.

Consider the following equation of Bernoulli's theorem

$\mathrm{P} + \frac{1}{2}{\mathrm{\rho v}}^2 + \mathrm{\rho gh} = \mathrm{K}$ (constant)

The dimensions of K/P are same as that of which of the following?

• Thrust

• Pressure

• Angle

• Viscosity

Why the dam of the water reservoir is thick at the bottom?

• Quantity of water increases with depth

• Density of water increases with depth

• Pressure of water increases with depth

• Temperature of water increases with depth

When a drop splits up into a number of drops, then :

• Area increases

• Volume increases

• Energy is absorbed

• Energy is liberated

At which of the following temperature, the value of the surface tension of water is minimum?

• 4°C

• 25°C

• 50°C

• 75°C

In a capillary tube experiment, a vertical, 30 cm long capillary tube is dipped in water. The water rises upto a height of 10 cm due to capillary action. If this experiment is conducted in a freely falling elevator, the length of the water column becomes :

• 10 cm

• 20 cm

• 30 cm

• zero

An aeroplane gets its upward lift due to a phenomenon described by the :

• Archimedes principle

• Bernoulli's principle

• Buoyancy principle

• Pascal law