40. 'in a thermodynamic system at equilibrium heat can be partially converted into work while the work can be completely converted to heat, this statement repre

40. 'In a thermodynamic system at equilibrium heat can be partially converted into work while the work can be completely converted to heat, this statement represents (A) Zeroth law of thermodynamics (B) First law of thermodynamics (C) Second law of thermodynamics (D) Third law of thermodynamics