Define thrust and pressure. Give their units. Show that when a liquid is in equilibrium, forces acting on the liquid must be perpendicular to its free surface.

Vapour pessure of a liquid or a solution is the pressure exerted by the vapour in equilibrium with the liquid or solution at a particular temperature. It depends upon the nature of the liquid and temperature. It depends upon the nature of the liquid and temperature. According to Raoult's law in a solution, the vapour pressure of a component at a given temperature is equal to the mole fraction of that component in solution multiplied by the vapour pressure of that component in hte pue state. this solution in which each component obeys Raoult's law are called ideal solutions. there are two types of non ideal solutions, showing positive deviations and negative deviations from ideal behaviour. If liquid A and B form ideal solution, then

A liquid is equilibrium with its vapours in a sealed container at a fixed temperature. The volume of the container suddenly increased. What happens when equilibrium is restored finally and what will be the final vapour pressure.

Define the term electric dipole moment. Give its units Derive an expression for the maximum torque acting on an electric dipole, when held in a uniform electric field.

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A). If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if asssertion is true, but reason if false, (D) if both assertion and reason are false Assertion : The energy of a charged particle does not change, when it moves inside the magnetic field. Reason: It is because, force on the charged particle due to the magnetic field acts perpendicular to its path.

A piece of uniform string hangs vertically so that its free end just touches horizontal surface of a table. The upper end of the strig is now released. Show that at any instant during the falling of string, the total force on the surface is three times the weight of that part of string lying on the surface.

A horizontal wire AB of length 'l' and mass 'm' carries a steady current I_1 , free to move in vertical plane is in equilibrium at a heigh of 'h' over another parallel long wire CD carrying a steady current I_2 , which is fixed in a horizontal plane as shown. Derive the expression for the force acting per unit length on the wire AB and write the condition for which wire AB is in equilibrium.