<prompt> Free water clearance is positive when urine isDiluteConcentrateIsotonicAny of the above  <response>: Ans. is a i.e., DiluteRef: Principles of Medical Physiology p 39IlKidney excretes some solutes in the urine daily.The volume of tater in urine, excreted per unit time in excess of thot required to excrete the contained solutes is-osmotically with plasma.Free water clearance is positive in dilute urine, negative where concentrated urine is passed and zero when isotonic urine is passed. 