Electrical measurements: Resistance is measured in which unit in the International System of Units (SI)?
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Aohms
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Bfarads
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Chelids
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Damperes
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Evolts
Answer
Correct Answer: ohms
Explanation
Introduction / Context:Understanding base electrical units is foundational for anyone working with circuits. Resistance quantifies how strongly a component opposes the flow of electric current.
Given Data / Assumptions:
- We seek the unit of resistance, not of current, voltage, or capacitance.
- SI units and standard electrical terminology are expected.
Concept / Approach:
Ohm’s law relates voltage (V), current (I), and resistance (R) by V = I * R. Rearranging shows that resistance equals voltage divided by current. The SI unit is therefore volt per ampere, named the ohm (symbol Ω). Digital multimeters display resistance directly in ohms, kilo-ohms, or mega-ohms depending on the magnitude.
Step-by-Step Solution:
Recall Ohm’s law: V = I * R.Solve for R: R = V / I.Identify SI unit: volt / ampere = ohm.Verification / Alternative check:
Instrument manuals and component datasheets list resistive values in Ω, kΩ, or MΩ, confirming the standard.
Why Other Options Are Wrong:
- Farads: Capacitance.
- Helids: Not an electrical unit.
- Amperes: Current.
- Volts: Voltage.
Common Pitfalls:
Misreading resistor color codes; confusing kilo-ohms and mega-ohms; measuring resistance in-circuit while other paths distort readings.
Final Answer:
ohms