Basic electrical quantity recall: In circuit theory, resistance is measured in which unit?

Difficulty: Easy

Correct Answer: ohms

Explanation:

Introduction / Context:Fundamental SI units underpin all electrical engineering calculations. Resistance quantifies opposition to current flow and is central to Ohm’s law and power dissipation analysis.

Given Data / Assumptions:

  • Quantity: electrical resistance.
  • Relevant relationships: V = I * R and P = I^2 * R = V^2 / R.
  • We need the correct SI unit name.

Concept / Approach:Recall that resistance is measured in ohms, symbol Ω, named after Georg Ohm. Other listed units measure different physical quantities and therefore are distractors by design.

Step-by-Step Solution:

Identify the physical quantity: resistance (R).Associate the SI unit: ohm (Ω).Select the matching text option: 'ohms'.

Verification / Alternative check:Dimensional analysis: From V = I * R, R = V / I, so the ohm equals volt per ampere, consistent with SI derivation. No other option matches V/A.

Why Other Options Are Wrong:

  • henries: unit of inductance (H).
  • hertz: unit of frequency (Hz).
  • watts: unit of power (W).

Common Pitfalls:

  • Confusing symbol Ω (ohm) with W (watt) when handwriting.
  • Assuming 'ohm' is only a symbol; the pluralized word 'ohms' is standard in text.

Final Answer:ohms

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