What unit is used to measure electric charge in Coulomb's law?

What unit is used to measure electric charge in Coulomb's law?

• A. Watt
• B. Newton
• C. Joule
• D. Coulomb

Answer: (D)

Electric charge is measured in Coulombs. In Coulomb's law, the charges q1 and q2 are the amounts of charge on two objects, and these quantities are expressed in Coulombs. The proportionality constant k is defined so that the equation works dimensionally when the charges are in Coulombs, which reinforces that Coulombs are the standard unit for charge. A Coulomb is defined as the amount of charge moved by a current of one ampere in one second, linking the concept of charge to current and time. The other units—Watt (power), Newton (force), and Joule (energy)—describe different quantities, so they don’t measure electric charge.

Electric charge is measured in Coulombs. In Coulomb's law, the charges q1 and q2 are the amounts of charge on two objects, and these quantities are expressed in Coulombs. The proportionality constant k is defined so that the equation works dimensionally when the charges are in Coulombs, which reinforces that Coulombs are the standard unit for charge. A Coulomb is defined as the amount of charge moved by a current of one ampere in one second, linking the concept of charge to current and time. The other units—Watt (power), Newton (force), and Joule (energy)—describe different quantities, so they don’t measure electric charge.