Current through an input resistor A binary-weighted DAC input resistor is 100 kΩ and is tied to a 5 V source. What current flows through this resistor (ideal conditions)?

Introduction / Context:
Ohm’s law is frequently applied when analyzing DAC input networks to determine branch currents from known resistor values and reference voltages.

Given Data / Assumptions:

• R = 100 kΩ.
• V = 5 V applied across the resistor.
• Ideal components (no leakage paths).

Concept / Approach:
Use Ohm’s law: I = V / R.

Step-by-Step Solution:
Compute: I = 5 / 100,000 = 0.00005 A.Convert to microamperes: 0.00005 A = 50 µA.

Verification / Alternative check:
Check units: volts/ohms = amperes; 5/1e5 = 5e−5 A confirms 50 µA.

Why Other Options Are Wrong:
5 mA / 500 µA / 50 mA: off by factors of 100–1000; likely from wrong kilo-to-base conversions.

Common Pitfalls:
Misplacing decimal points when converting kΩ to Ω.

Final Answer:
50 µA