Response:
In primary cells, an electric potential arises due to chemical reactions occurring between the internal plates. Zinc ions, which are positively charged, move into the acid, while freed electrons from zinc atoms accumulate on the zinc plate, leading to a negative charge. Concurrently, positively charged hydrogen ions from the acid strip electrons from the copper plate, giving it a positive charge. Electrons transition from the zinc plate to the copper plate through a conductor for the duration of the chemical reaction.
Dry cells create electric potential similarly through internal chemical processes. Electrons taken from a carbon rod gather on a zinc can, resulting in a positive charge on the rod and a negative charge on the can; thus establishing an electric potential between them. As long as the conductive link remains intact, electrons transfer from the can to the rod.
Electric potential in generators is produced through magnetic induction. When a conductive rod is moved within the magnetic field of a horseshoe magnet, it generates an electric potential along the rod. Electrons travel through the rod from one end to the other for as long as the movement persists. The direction of movement is influenced by whether the rod is being moved against or with the magnetic field lines. Generators typically consist of several conductors fixed onto a rotating cylinder situated in a magnetic field.
Thermocouples convert heat to electric potential. A junction is created by connecting two metal strips at one end, while their other ends remain separated. Heating the junction raises the temperature of both strips. The ends that are not heated generate electric charges due to differing temperatures. Connecting these ends with a conductive wire allows electrons to flow through. The voltage generated increases with the temperature difference between the ends and the junction.
a. Increase
b. Decrease
c. Decrease
To convert watt-hours (Wh) to British thermal units (Btu), divide the Wh amount by 0.293, since 1 Btu = 0.293 Wh. Thus, 0.8 ÷ 0.293 = 2.73 Btu
Calculating energy usage: 365 days × 10 hours × 40 W = 146,000 Wh, equivalently 146 kWh
Clarification:
Penn Foster
