A refrigerator has to transfer an averageof 200 Joule ofheat per sec from temperature -`10^@C` to `+25^@C`. Calculate the average power consumed assuming ideal reversible cycle and no other losses.

A fog drop has a diameter of 2xx10^-6 m. Calculate the pressure inside the drop in atmospheres , if the temperature is 20^@ C. Assume the air pressure outside the drop one atmosphere and surface tension of water=0.0727N/m (1atm=1.013xx10^5N/m^2) .

A brass disc at a 20^@C has a diameter of 30 cm and a hole cut in the centre is 10 cm in diameter. Calculate the diameter of the hole when temperature of the disc is raised to 50^@C . The coefficient of linear expansion of brass= 0.000018 per^@C .

A steel rod is 3.000 cm in diameter at 25^@C . A brass ring has an interior diameter of 2.992 cm at 25^@C . At what common temperature will the ring just slide onto the rod ? (Coefficient of linear expansion of steel= 12 xx 10^(-6) per k and coefficient of linear expansion of brass= 18 xx 10^(-6) per k) .

The ionisation constant of NH_4^+ in water is 5.6xx10^(-10) at 25^@C the rate constant for the reaction of NH_4^+ and OH^- to form NH_3 and H_2O at 25^@C IS 3.4xx10^10 L mol/sec Find the rate constant for proton transfer from water to NH_3 ?