A substance absorbs heat `Q_1`, in going from one state to another and releases `Q_2` in coming from the second state to the first state. How much work is done by the substance and what is the change in* the internal energy of the substance.?

What will be the change in internal energy of a system if no work is done on the system but q amount of heat is taken out from the system and given to the surroundings.

What is gravitational potential energy at a point? How much of work is done in shifting mass from the surface to a height equal to its radius?

In changing the state of a gas adiabaticaiiy from an equilibrium state A to another equilibrium state B, an amount of work equal to 22.3 J is done on the system. If the gas is taken from state A to B via a process in which the net heat absorbed by the system is 9.35 cal, how much is the net work done by the system in the latter case? (Take 1 cal = 4.19 J)

A rain drop of radius 2 mm falls from a height of 500 m above the ground. It falls with decreasing acceleration (due to viscous resistance of the air) until at half its original height, it attains its maximum (terminal) speed, and moves with uniform speed thereafter. What is the work done by the gravitational force on the drop in the first and second half of its journey? What is the work done by the resistive force in the entire journey if its speed on reaching the ground is 10 m s-^1 ?

State Faraday's first law. How much charge in terms of Faraday is required for the reduction of 1 mole of Cu^(2+) to Cu?

In an electric filed a unit positive charge is displaced from one point to another point along a straingt line of length 2cm and the work done is 2mJ. If it is displaced along a parabilic path between the same points of length 5 cm, What will be the work done?

If the inter - molicule potential energy is minimum at separation R0 what prevents the molecules ofa a substance from collasping to the condensed state ?