Difficulty: Easy
Correct Answer: 25 mW
Explanation:
Introduction / Context:
Engineering problems frequently require converting between watts and submultiples such as milliwatts and microwatts. Mastering metric prefixes avoids scale errors and enables quick interpretation of specifications for sensors, amplifiers, and power supplies.
Given Data / Assumptions:
Concept / Approach:
Use unit equivalences and multiply/divide by powers of ten. Converting watts to milliwatts requires multiplying by 10^3. Converting watts to microwatts requires multiplying by 10^6.
Step-by-Step Solution:
Verification / Alternative check:
Reverse conversion: 25 mW / 1000 = 0.025 W. This confirms the accuracy.
Why Other Options Are Wrong:
2,500 µW = 2.5 mW = 0.0025 W (ten times smaller). 0.00025 mW = 2.5 * 10^-7 W (far smaller). 25 kW is 25,000 W (enormously larger). 250 µW = 0.00025 W (much smaller).
Common Pitfalls:
Misplacing decimal points, confusing mW with µW, and forgetting that k (kilo) is 10^3 while m (milli) is 10^-3.
Final Answer:
25 mW
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