What is the SI unit of charge?

What is the SI unit of charge?

• A. Coulomb, C
• B. Joule, J
• C. Volt, V
• D. Watt, W

Answer: (A)

Charge is a quantity tied to the flow of electric current over time. In the SI system, the unit of electric charge is the coulomb. One coulomb is the amount of charge that passes a point when a steady current of one ampere flows for one second. Since current equals charge per time (Q = I × t), the coulomb is essentially an ampere-second. The other units correspond to different quantities: joule for energy, volt for electric potential difference, and watt for power, so they are not units of charge.

Charge is a quantity tied to the flow of electric current over time. In the SI system, the unit of electric charge is the coulomb. One coulomb is the amount of charge that passes a point when a steady current of one ampere flows for one second. Since current equals charge per time (Q = I × t), the coulomb is essentially an ampere-second. The other units correspond to different quantities: joule for energy, volt for electric potential difference, and watt for power, so they are not units of charge.