What is the energy change when 1 coulomb of charge passes through a potential difference of 1 volt?

What is the energy change when 1 coulomb of charge passes through a potential difference of 1 volt?

• A. Volt; gains 1 J of energy
• B. The unit of charge
• C. Joule
• D. Ampere

Answer: (A)

The key idea is that the energy change when a charge moves through a potential difference is ΔE = qV. With a charge of 1 coulomb and a potential difference of 1 volt, the energy change is ΔE = 1 C × 1 V = 1 joule. A volt is defined as 1 joule per coulomb, so moving 1 coulomb through 1 volt indeed yields 1 joule of energy gained. The option that mentions the volt and states the energy gain as 1 joule correctly ties together the potential difference unit with the resulting energy. The other choices don’t fit because they either refer to a different quantity (the unit of charge or current) or only name the energy unit without connecting it to the potential difference.

The key idea is that the energy change when a charge moves through a potential difference is ΔE = qV. With a charge of 1 coulomb and a potential difference of 1 volt, the energy change is ΔE = 1 C × 1 V = 1 joule. A volt is defined as 1 joule per coulomb, so moving 1 coulomb through 1 volt indeed yields 1 joule of energy gained. The option that mentions the volt and states the energy gain as 1 joule correctly ties together the potential difference unit with the resulting energy. The other choices don’t fit because they either refer to a different quantity (the unit of charge or current) or only name the energy unit without connecting it to the potential difference.