Physiology General 5496fe03 In normal adult Vd/Vt ratio is: A 20 B 0.35 C 40 D 50 High-Yield Explanation B i.e. 0.35Vd = Dead space volume & Vt = Tidal Volume, so Vd/Vt = 150 = 0.3 100Normal value of Vd/Vt in adults = 0.2 - 0.35Q