What is the correct unit for inductance?

What is the correct unit for inductance?

• A. The unit of resistance
• B. The unit of inductance
• C. The unit of power
• D. Henry

Answer: (D)

Inductance is measured in henries. This comes from the defining relation ε = -L di/dt, where the induced emf ε equals the inductance L times the rate of change of current. Rearranging, L = ε / (di/dt). Since ε is in volts and di/dt is in amperes per second, the units are V / (A/s) = V·s / A, which is defined as one henry. Put another way, 1 H means a circuit where a current changing at 1 A/s induces 1 volt. The other options refer to different quantities: resistance is ohms, power is watts, while the unit for inductance is the henry.

Inductance is measured in henries. This comes from the defining relation ε = -L di/dt, where the induced emf ε equals the inductance L times the rate of change of current. Rearranging, L = ε / (di/dt). Since ε is in volts and di/dt is in amperes per second, the units are V / (A/s) = V·s / A, which is defined as one henry. Put another way, 1 H means a circuit where a current changing at 1 A/s induces 1 volt. The other options refer to different quantities: resistance is ohms, power is watts, while the unit for inductance is the henry.