Ohm’s law (repaired for solvability): A DC source drives a 2.5 kΩ load and the measured current is 10 mA. What is the supply voltage in the circuit?

Difficulty: Easy

2.5 V
25 V
250 V
2.5 kV

Correct Answer: 25 V

Explanation:

Introduction / Context:
Ohm’s law is the foundational relationship among voltage, current, and resistance in linear circuits. Given any two of the three quantities, the third is determined uniquely. This problem asks you to compute the supply voltage that produces a given current through a known resistance.

Given Data / Assumptions:

Resistance R = 2.5 kΩ (i.e., 2500 Ω).
Current I = 10 mA (i.e., 0.010 A).
Steady DC conditions; wiring drops are negligible.

Concept / Approach:
Use V = I * R. Be careful with unit prefixes: kilo (10^3) for ohms and milli (10^-3) for amperes. Multiply the base units to avoid mistakes, then convert back to convenient engineering units (volts).

Step-by-Step Solution:

Write V = I * R.Insert I = 0.010 A and R = 2500 Ω.Compute V = 0.010 * 2500 = 25 V.Therefore, the supply voltage is 25 V.

Verification / Alternative check:
Cross-check with current: I = V / R = 25 / 2500 = 0.010 A = 10 mA, confirming consistency.

Why Other Options Are Wrong:

2.5 V: would give 1 mA, not 10 mA.250 V and 2.5 kV: would produce 100 mA and 1 A respectively, far above the stated 10 mA.

Common Pitfalls:
Mixing kilo and milli prefixes; forgetting to convert mA to A before multiplying.

Ohm’s law (repaired for solvability): A DC source drives a 2.5 kΩ load and the measured current is 10 mA. What is the supply voltage in the circuit?

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