Power equivalence with mixed units: For a circuit operating at 12 V with a current of 40 mA, what is the power expressed in different unit forms?

Introduction / Context:Being able to compute electrical power and express it in equivalent units is a core skill in basic circuit analysis and electronics troubleshooting. This question evaluates your fluency with P = V * I and with converting between watts (W), milliwatts (mW), and microwatts (µW).

Given Data / Assumptions:

• Voltage V = 12 V (direct current or RMS equivalent).
• Current I = 40 mA = 0.04 A.
• Power relation P = V * I applies to resistive loads (or RMS quantities).

Concept / Approach:Use the fundamental power equation P = V * I, then convert the numerical result into different unit scales. Remember that 1 W = 1,000 mW and 1 W = 1,000,000 µW. Consistent unit conversion is crucial for component selection and power budgeting.

Step-by-Step Solution:

Verification / Alternative check:Cross-check using P = I^2 * R or P = V^2 / R if resistance is known; here, dimensional checks confirm the unit conversions. The three numerical forms represent the same physical power.

Why Other Options Are Wrong:

• Each individual value is correct; therefore, the best choice is the inclusive option stating all are correct.

Common Pitfalls:

• Forgetting to convert milliamperes to amperes before multiplying by volts.
• Confusing mW and µW scaling factors (10^3 vs 10^6).

Final Answer:all of the above