Electrical quantities — correct SI unit and symbol for electric current What are the SI unit and the standard symbol used to denote electric current?

Introduction / Context:
Using correct SI units and symbols is essential for clear communication in engineering calculations and schematics. Electric current has a defined base unit and a standard symbol in the International System of Units (SI).

Given Data / Assumptions:

• We are asked for both the SI unit name and the printed unit symbol.
• We distinguish between unit symbols and variable symbols used in equations.

Concept / Approach:
The SI base unit of current is the ampere with symbol A. In circuit equations, current is often denoted by the variable i or I, but the official unit symbol remains A. Coulomb (C) is the unit of electric charge, not current; Q commonly denotes charge, not current.

Step-by-Step Solution:
Identify the SI base unit for current: ampere.Confirm the unit symbol: A.Distinguish variable symbols (I, i) from unit symbols; select Ampere, A.

Verification / Alternative check:
SI Brochure lists ampere (A) as the base unit; Coulomb equals amperesecond (C = As).

Why Other Options Are Wrong:

• Coulomb, I: Coulomb measures charge, not current.
• Ampere, Q: Q is used for charge, not the unit symbol for current.
• Ampere, I: I is a variable symbol in equations, not the SI unit symbol.

Common Pitfalls:

• Mixing up variable notation (I) with SI unit symbol (A).

Final Answer:
Ampere, A