An horizontal insulated cylindrical vessel of length 2l is separated by a thin insulating piston into two equal parts as shown. Each part contains n moles of an ideal monoatomic gas at temperature T. The piston is connected to end faces of cylinder with help of two springs each of spring constank k. Initially both springs are in relaxed state. The temperature of left part of cylinder is kept constant by some external means while heat is supplied to right part with help of filament. Answer following questions.
If energy Q is supplied to right part so that the piston moves to left by l/4 then change in internal energy of right part of cylinder is