Apply Ohm’s law: A 24 Ω resistor carries 4 A when connected to a source. What voltage does the source provide?

Introduction / Context:
This is a direct substitution exercise with Ohm’s law, used daily to relate voltage, current, and resistance in basic circuits. Accurate substitution is essential when sizing power supplies and verifying test conditions.

Given Data / Assumptions:

• Resistance R = 24 Ω.
• Current I = 4 A.
• Goal: source voltage V.

Concept / Approach:
Ohm’s law states V = I * R. Multiply current by resistance to find the terminal voltage that produces the specified current through the given resistor.

Step-by-Step Solution:

Verification / Alternative check:
Check power as a consistency test: P = V * I = 96 * 4 = 384 W, and also P = I^2 * R = 16 * 24 = 384 W. Both agree, confirming the result.

Why Other Options Are Wrong:

• 960 V: Off by a factor of 10; would imply P = 3840 W.
• 9.6 V: Too small by a factor of 10; would give I = 0.4 A.
• 8 V: Would yield I = 8 / 24 = 0.333 A, not 4 A.

Common Pitfalls:

• Mistaking decimal placement and producing a factor-of-ten error.
• Mixing up formulas such as R = V / I instead of solving for V directly.

Final Answer:
96 V