Numerical branch current — if a branch resistor has 5.00 V across it and its resistance is 237 Ω, what is the branch current (choose the closest value)?

Introduction / Context:
Applying Ohm’s law to compute a branch current from a measured branch voltage is a routine but essential skill. This question provides a realistic resistor value (237 Ω, an E24/E96 series style) and a neat round voltage to check unit handling and arithmetic accuracy.

Given Data / Assumptions:

• Branch voltage V = 5.00 V (across the resistor).
• Resistance R = 237 Ω.
• Linear operation; temperature and tolerance effects ignored.

Concept / Approach:
Use Ohm’s law: I = V / R. Convert the result into an appropriate unit (amperes or milliamperes) and round sensibly to match the options while retaining significant figures consistent with the inputs provided.

Step-by-Step Solution:

Verification / Alternative check:
Cross-check by estimating: 5 V across 250 Ω would be 20 mA; since 237 Ω is a bit lower than 250 Ω, current should be a bit higher than 20 mA — around 21 mA. This aligns with the exact calculation 21.11 mA.

Why Other Options Are Wrong:

• 10 mA: Would require about 500 Ω at 5 V; not our case.
• 90 mA or 100 mA: Would imply ~55 Ω to 50 Ω at 5 V; far from 237 Ω.

Common Pitfalls:
Mistaking milliamps for amps (writing 0.0211 mA), or rounding too early. Keep unit consistency and convert at the end.

Final Answer:
21.11 mA is the correct branch current for 5.00 V across 237 Ω.