Difficulty: Easy
Correct Answer: Correct
Explanation:
Introduction / Context:
This item originally referenced a “given circuit” without data. Applying the Recovery-First Policy, we minimally repaired the stem by stating the initial current explicitly and assuming a fixed-resistance DC circuit. The concept being tested is the direct proportionality between current and voltage for a constant resistance, as stated by Ohm’s law.
Given Data / Assumptions:
Concept / Approach:
Ohm’s law gives I = V / R or equivalently V = I * R. With R fixed, voltage and current are directly proportional. Therefore, any multiplicative change in current requires the same multiplicative change in voltage. Tripling the current requires tripling the voltage at constant resistance.
Step-by-Step Solution:
Verification / Alternative check:
Numerical example: If R = 1 kΩ, then V1 = 8 mA * 1 kΩ = 8 V and V2 = 24 mA * 1 kΩ = 24 V, confirming a 3x increase. The specific R cancels in the ratio, so the conclusion does not depend on its value.
Why Other Options Are Wrong:
Common Pitfalls:
Forgetting to specify that resistance is constant; mixing peak and RMS when dealing with AC; assuming the conclusion depends on a particular resistance value when the ratio makes it independent.
Final Answer:
Correct.
Discussion & Comments