Applying Ohm’s law: which formula directly yields the current through a resistor when the voltage across it (E) and its resistance (R) are known?

Introduction / Context:
Ohm’s law is the cornerstone of circuit analysis, relating voltage (E), current (I), and resistance (R). When you know the voltage across a resistor and its resistance value, a specific rearrangement of Ohm’s law gives current directly. Correctly choosing this form speeds analysis and avoids unnecessary steps.

Given Data / Assumptions:

• Resistive element obeys Ohm’s law.
• Known quantities: E and R.
• Desired unknown: I.

Concept / Approach:
Starting from the canonical relation E = I * R, solve for current by dividing both sides by R to obtain I = E / R. This direct form is used constantly in electronics to compute current from known applied voltage across a component and its resistance value in ohms.

Step-by-Step Solution:

Verification / Alternative check:
Unit analysis: volts / ohms = amperes. Example: E = 10 V, R = 5 Ω → I = 2 A, which is consistent with common circuit intuition and power calculations.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing P = I * E and E = I * R; ensure you are solving specifically for I with known E and R.

Final Answer:
I = E / R