Which statement is a direct expression of Ohm law for a passive resistor?

Introduction / Context:
Ohm law is the cornerstone of resistive circuit analysis. It relates voltage, current, and resistance in a simple proportional law used in nearly every calculation from bias networks to power estimation.

Given Data / Assumptions:

• Passive, linear resistor behavior in the considered operating range.
• Temperature and self-heating effects are negligible.
• DC or AC steady-state conditions are acceptable for the proportional relation.

Concept / Approach:
Ohm law states V = I * R. Therefore, the voltage drop across a resistance is directly proportional to current and proportional to resistance. This is a direct statement of the law. The law enables simple series-parallel reductions and power calculations with P = V * I = I^2 * R = V^2 / R.

Step-by-Step Solution:
1) Recall the relation V = I * R.2) Interpret: for a given R, voltage varies linearly with current; for a given I, voltage scales with R.3) Select the statement that explicitly expresses this proportionality.

Verification / Alternative check:
Plotting V versus I for a resistor yields a straight line with slope R, confirming the proportional relationship.

Why Other Options Are Wrong:

• Option B: True property of parallels but not Ohm law.
• Option C: This is Kirchhoff Voltage Law, not Ohm law.
• Option D: This is Kirchhoff Current Law, not Ohm law.
• Option E: Incorrect because Option A is correct.

Common Pitfalls:
Confusing Ohm law with Kirchhoff laws or network theorems is common. Always tie Ohm law to the element relation of a resistor only.

Final Answer:
The voltage drop across a resistance is proportional to the value of resistance and the amount of current flowing through it.