Surface Tension...

What is the excess pressure inside a bubble of soap solution of radius 5.00 mm, given that the surface tension of soap solution at the temperature (20° C20° C) is 2.50 × 10^–2 N/m?

Two narrow bores of diameters 3.0 mm and 6.0 mm are joined together to form a U-tube open at both ends. If the U-tube contains water, what is the difference in its levels in the two limbs of the tube? The surface tension of water at the temperature of the experiment is 7.3 × 10^–2 N m^–1. Take the angle of contact to be zero and the density of water to be 1.0 × 10³ kg m^–3 (g = 9.8 m s^-2).

Soap helps in cleaning clothes, because

On increasing temperature of a liquid, its surface tension generally

The raincoats are made water proof by coating it with a material, which

An iron needle slowly placed on the surface of water floats because

Two water droplets merge with each other to form a larger droplet. In this process

The radius of a soap bubble is r. The surface tension of soap solution is 'S'. Keeping temperature constant, the radius of the soap bubble is soubled. The energy necessary for this will be

The surface tension of a liquid is 5 N/m. If a film is held on a ring of area 0.02 m², its surface energy is about

Two soap bubbles having radii 3 cm and 4 cm in vacuum, coalesce under isothermal conditions. The radius of the new bubble is