Ohm's law describes the mathematical relationship between which set of quantities used to calculate basic circuit behavior?

Electronics Ohm's Law Difficulty: Easy
Choose an option
  • A
    ohms, kilohms, and megohms
  • B
    resistor size and resistor value
  • C
    resistance, voltage, and current
  • D
    none of the above
  • E
    power factor, frequency, and phase

Answer

Correct Answer: resistance, voltage, and current

Explanation

Introduction:This question reinforces the definition of Ohm's law from a descriptive angle. Correctly identifying the variables tied by the law is essential for solving everyday circuit problems, from selecting series resistors for LEDs to estimating supply current.

Given Data / Assumptions:

  • Ohmic components with linear V–I behavior.
  • Steady-state conditions for DC, or instantaneous relationships for resistive AC.

Concept / Approach:Ohm's law: V = I * R links voltage (V), current (I), and resistance (R). Units (ohms, kilohms, megohms) are scales of resistance, not separate physical quantities governed by the law.

Step-by-Step Solution:Recognize variables: resistance (R), voltage (V), current (I).Recall the identity: V = I * R.Derive forms: I = V / R and R = V / I.Apply to examples: choose R to set I for a given V in a simple series circuit.

Verification / Alternative check:Plotting measured current against applied voltage for a fixed resistor yields a straight line with slope 1/R, confirming the relationship between the three quantities.

Why Other Options Are Wrong:

  • ohms, kilohms, and megohms: Merely unit prefixes for resistance.
  • resistor size and resistor value: Physical size does not define the Ohm's law relationship.
  • none of the above / power factor set: Do not describe Ohm's law.

Common Pitfalls:

  • Assuming large physical resistors always have large resistance; power rating and resistance are different specifications.
  • Confusing derived power equations with the primary Ohm's law identity.

Final Answer:resistance, voltage, and current

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