Difficulty: Easy
Correct Answer: I x R
Explanation:
Introduction / Context:
Ohm's law connects voltage, current, and resistance, allowing you to compute voltage drops across components. Correctly recalling the form of this relationship is crucial for sizing parts, predicting behavior, and diagnosing faults in DC and AC circuits alike.
Given Data / Assumptions:
Concept / Approach:
Ohm's law states V = I * R for an ohmic element. This is the constitutive relation for resistors and follows from the proportionality between electric field and current density in a uniform conductor. Power relations such as P = I^2 * R or P = V * I are derived, not primary for finding voltage drop directly.
Step-by-Step Solution:
Start with Ohm's law: V = I * R.Identify given quantities: I (current), R (resistance).Compute voltage drop using multiplication of I and R.Therefore, the correct expression is I x R.
Verification / Alternative check:
If power P is known, P = I^2 * R and P = V * I. Solving P = V * I for V gives V = P / I. Substituting P = I^2 * R yields V = (I^2 * R) / I = I * R, confirming the same relationship from power formulas.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
I x R
Discussion & Comments