Energy Conversions in Fuel Cells

The video tutorial demonstrates the process of using a solar cell to power a fan, then connecting it to a hydrogen fuel cell to produce hydrogen and oxygen. The instructor explains the setup, the connection process, and the observation of gas production. The tutorial further explores disconnecting the fuel cell from the solar cell and reversing it to power a fan, illustrating the conversion of light energy to chemical energy and then to electricity. The video concludes with a discussion on the efficiency of the system as hydrogen and oxygen levels decrease.

What is the initial purpose of the solar cell in the setup?

• To power a light bulb

• To drive a fan

• To charge a battery

• To heat water

What happens when the red and black sides are connected to the hydrogen fuel cell?

• The fan stops working

• Hydrogen and oxygen are produced

• The solar cell is disconnected

• The motor reverses direction

At what rate is oxygen produced compared to hydrogen in the fuel cell?

• At the same rate

• Three times the rate

• Twice the rate

• Half the rate

What is the role of sunlight in the hydrogen fuel cell process?

• It splits water into hydrogen and oxygen

• It cools the system

• It powers the fan directly

• It heats the water

What is the next step after reaching the maximum rate of hydrogen production?

• Connect the fan directly to the fuel cell

• Disconnect the fan

• Stop the solar cell

• Increase the sunlight intensity

What energy conversion takes place when the fan is connected directly to the fuel cell?

• Light to sound

• Chemical to thermal

• Mechanical to chemical

• Chemical to electrical

Why does the system gradually slow down over time?

• The motor overheats

• The solar cell loses power

• The fan is too heavy

• The pressure of hydrogen and oxygen decreases

What is the main reason for the reduced pressure in the system?

• The motor is faulty

• The solar cell is disconnected

• Hydrogen and oxygen are used up

• The fan consumes too much energy

How much hydrogen is used to power the system by the end of the process?

• Ten to eleven cm³

• Eight to nine cm³

• Four to five cm³

• Two to three cm³

What is the final outcome of the energy conversion process demonstrated?

• Chemical energy is converted to electricity

• Sound energy is produced

• Light energy is stored as heat

• Mechanical energy is converted to light