Inductance unit equivalence: One henry (H) is equal to which of the following unit ratios?

Introduction / Context:
Recognizing equivalent forms of SI units helps in dimensional analysis and understanding physical definitions. The henry (H) is the SI unit of inductance used widely in circuit theory, electromagnetics, and power systems.

Given Data / Assumptions:

• Standard SI base and derived units.
• Definition of inductance from magnetic flux–current relation or voltage–current dynamics.

Concept / Approach:

Inductance L is defined by the relations: flux linkage λ = L * I and v = L * di/dt for a linear inductor. From λ = N * Φ (for N turns) and L = λ / I, the unit of L is weber-turns per ampere; for one-turn, it reduces to weber per ampere. The voltage form v = L di/dt implies L has units of volt-second per ampere, which equals weber per ampere because 1 weber = 1 volt·second.

Step-by-Step Solution:

Verification / Alternative check:

Dimensional analysis with base units: H = kg·m^2·s^−2·A^−2, consistent with Wb/A and V·s/A identities.

Why Other Options Are Wrong:

• Volts/Ampere corresponds to resistance (ohm).
• Weber/Volt equals seconds (time), not inductance.
• Weber/Ampere2 is not a standard physical unit.

Common Pitfalls:

• Confusing Wb/A (inductance) with V/A (resistance) because both are ratios involving ampere.

Final Answer:

Weber/Ampere