Basic electrical quantity recall: In circuit theory, resistance is measured in which unit?
Electronics
Quantities and Units
Difficulty: Easy
Choose an option
-
Ahenries
-
Bohms
-
Chertz
-
Dwatts
Answer
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