Fundamental units — in SI (International System of Units), which unit is the correct unit of electric charge used throughout electronics and physics?

Introduction / Context:
Clear understanding of SI units is essential in circuit analysis, electromagnetics, and instrumentation. Electric charge is a primary quantity from which current, voltage relationships, and capacitor behavior are derived. This item checks if you can identify the proper SI unit for charge.

Given Data / Assumptions:

• Use of SI base and derived units.
• Standard definitions per the SI Brochure.
• No need to convert between systems; just identify the correct unit.

Concept / Approach:
The coulomb (symbol C) is the SI unit of electric charge. One coulomb corresponds to the charge transported by a current of one ampere in one second, so 1 C = 1 A * 1 s. Recognizing this definition also connects charge to capacitor equations such as Q = C_elec * V, where Q is charge (C), C_elec is capacitance (F), and V is voltage (V).

Step-by-Step Solution:

Verification / Alternative check:
Capacitor formula Q = C_elec * V uses coulombs on the left when capacitance is in farads and voltage in volts (since 1 F = 1 C/V).

Why Other Options Are Wrong:

• Ampere: Unit of electric current (charge per second), not charge itself.
• Volt: Unit of electric potential difference.
• Ohm: Unit of resistance.

Common Pitfalls:
Confusing charge with current due to their close relationship; remember current is the rate of flow of charge.

Final Answer:
coulomb