Units and measurements in basic electricity: Is the electrical resistance of a component measured in the SI unit called the ohm (symbol Ω)?

Difficulty: Easy

Correct Answer: True

Explanation:


Introduction / Context:
Units are the language of engineering. Recognizing the correct SI units for common electrical quantities is essential for interpreting datasheets, performing calculations, and communicating results accurately.



Given Data / Assumptions:

  • Quantity in question: electrical resistance.
  • We are verifying its standard SI unit and symbol.
  • No specialized unit system (e.g., CGS) is being used—assume SI.


Concept / Approach:

In the International System of Units (SI), resistance is measured in ohms, symbol Ω, named after Georg Ohm. Ohm’s law relates voltage, current, and resistance: V = I * R, where V is in volts (V), I in amperes (A), and R in ohms (Ω). This relationship is foundational across electronics and electrical engineering.



Step-by-Step Solution:

Identify the physical quantity: resistance (opposition to current flow).Recall SI base and derived units: resistance is a derived unit.Map to correct unit and symbol: ohm (Ω).Conclude the statement “Resistance is measured in ohm” is correct.


Verification / Alternative check:

Dimensional analysis: ohm = volt / ampere. Using base units, Ω = (kg * m^2) / (s^3 * A^2). Textbooks and standards (IEC/ISO) confirm Ω as the SI unit of resistance.



Why Other Options Are Wrong:

  • False: would imply another unit, which is incorrect in SI. Alternate related quantities use different units (e.g., conductance in siemens, Ω^-1).


Common Pitfalls:

Confusing resistance (Ω) with reactance (also expressed in ohms but frequency-dependent) or confusing resistance with resistivity (Ω·m). Ensure the correct quantity and symbol are applied.


Final Answer:

True

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