Fuel Cell Engines By: Matthew M. Mench 3.24 For a hydrogen PEFC based on the concepts in this chapter, do you expect the open-circuit voltage to (circle one): (a) Increase/decrease/stay the same if the cathode oxygen mole fraction increases (b) Increase/decrease/stay the same if the cathode total pressure increases (c) Increase/decrease/stay the same if the anode humidity is increased (d) Increase/decrease/stay the same if the operating temperature increases (e) Increase/decrease/stay the same if the cathode humidity is increased (f) Increase/decrease/stay the same if helium is mixed with the air before entry into the cathode