Voltage across a resistor — apply Ohm’s law with unit prefixes: What is the voltage across a 2.2 kΩ resistor if 3 mA of current flows through it?

Introduction / Context:This is a direct substitution problem using Ohm’s law. Correct handling of kilo-ohms and milliamperes is critical to avoid order-of-magnitude errors in the final voltage.

Given Data / Assumptions:

• R = 2.2 kΩ = 2200 Ω.
• I = 3 mA = 0.003 A.
• Linear resistor, steady state.

Concept / Approach:Use V = I * R, ensuring that units are in base SI prior to multiplication. Then express the answer in volts with sensible significant figures reflecting the inputs.

Step-by-Step Solution:

Verification / Alternative check:Back-check current: I = V / R = 6.6 / 2200 ≈ 0.003 A = 3 mA, confirming the result.

Why Other Options Are Wrong:

Common Pitfalls:Leaving R in kΩ and I in mA without adjusting; misplacing decimal points when using prefixes.

Final Answer:6.6 V