Calculate the amount of energy evolved when 8 droplets of water (Surface tension 0.072 `N m^-1)` of radius `1/2` mm each combines into one.

Find the amount of work done in blowing a soap bubble of surface tension 0.06 Nm^-1 from 2 cm radius to 5 cm radius.

Calculate the mass of of 1 mole of each one of the following : Na2O2

Calculate the amount of KCl which must be added to 1 kg of water so that its freezing point is depressed by 2 K.

Calculate the boiling point of one molar aquesous solution (density 1.03gmL^-1) of NaCl. K_b for water= 0.52Km^-1 .

Calculate the electric field in a copper wire of cross-sectional area 2.0 mm^2 carrying a current of 1 A. The conductivity of copper = 6.25 xx 10^7 S m^-1

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 ? Surface tension of water at the temperature of the experiment is 7.3xx 10^-2 N m^-1 '. Take the angle of contact to be zero and density of water to be 1.0xx 10^3 kg m^- 3 ( g = 9.8 m s^-2 ) .

A truck is pulling a car out of a ditch by means of a steel cable that is 9.1 m long and has a radius of 5 mm. When the car just begins to move, the tension in the cable is 800 N. How much has the cble streched ? (Young's modulus for steel is 2xx 10^11 N m^-2) .

Two separate air bubbles (radii 0.002 m and 0.004 m) formed of the same liquid (surface tension 0.70 Nm^-1)~ came together to form a double bubble. Find the radius and sense of curvature of the internal film surface common to both the bubbles.

Calculate the radius of oxygen nucleus .Given that R_0 = 1.1 xx 10^(-15) m .