The coulomb is the SI unit of which quantity?

The coulomb is the SI unit of which quantity?

• A. Charge
• B. Current
• C. Voltage
• D. Resistance

Answer: (A)

The key idea is that the coulomb defines the amount of electric charge. Current is the flow rate of charge, so it’s measured in amperes. Since current I equals charge Q divided by time t (I = Q/t), the unit of charge is the product of current and time: 1 coulomb equals 1 ampere times 1 second (1 C = 1 A·s). So the coulomb is a unit for charge, not for current, voltage, or resistance. For context, voltage is measured in volts and resistance in ohms, while current is measured in amperes. One coulomb corresponds to about 6.24×10^18 elementary charges (electrons) in magnitude.

The key idea is that the coulomb defines the amount of electric charge. Current is the flow rate of charge, so it’s measured in amperes. Since current I equals charge Q divided by time t (I = Q/t), the unit of charge is the product of current and time: 1 coulomb equals 1 ampere times 1 second (1 C = 1 A·s). So the coulomb is a unit for charge, not for current, voltage, or resistance. For context, voltage is measured in volts and resistance in ohms, while current is measured in amperes. One coulomb corresponds to about 6.24×10^18 elementary charges (electrons) in magnitude.