Which is equal to 500 milliwatts?
The correct answer is B: 0.5 watts. 500 milliwatts equals 0.5 watts. The prefix 'milli-' means one-thousandth, so 1 milliwatt = 0.001 watts. To convert milliwatts to watts, divide by 1,000.
500 mW ÷ 1,000 = 0.5 W. This is a straightforward power unit conversion. Milliwatts (mW) are commonly used for small power levels (like receiver power consumption), while watts (W) are used for larger power levels (like transmitter output). Understanding these conversions is important for reading equipment specifications.
Exam Tip
Milliwatts to watts = Divide by 1000. Remember: To convert milliwatts to watts, divide by 1,000. 500 mW ÷ 1000 = 0.5 W.
Memory Aid
"**M**illiwatts **T**o **W**atts = **M**ove **T**hree **D**ecimal **P**laces **L**eft (think 'MTW = MTDPL' = Move Three Decimal Places Left, divide by 1000)"
Real-World Application
Your handheld transceiver might consume 500 milliwatts (0.5 watts) when receiving. This is a very low power consumption, which is why handhelds can operate for many hours on a small battery. Understanding that 500 mW = 0.5 W helps you understand power consumption specifications and calculate battery life.
FCC Part 97.313Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. 0.02 watts equals 20 milliwatts, not 500 milliwatts. You're off by a factor of 25.
Option C: Incorrect. 5 watts equals 5,000 milliwatts, not 500 milliwatts. You multiplied instead of dividing.
Option D: Incorrect. 50 watts equals 50,000 milliwatts, way too large. You're off by a factor of 100.
题目解析
The correct answer is B: 0.5 watts. 500 milliwatts equals 0.5 watts. The prefix 'milli-' means one-thousandth, so 1 milliwatt = 0.001 watts. To convert milliwatts to watts, divide by 1,000. 500 mW ÷ 1,000 = 0.5 W. This is a straightforward power unit conversion. Milliwatts (mW) are commonly used for small power levels (like receiver power consumption), while watts (W) are used for larger power levels (like transmitter output). Understanding these conversions is important for reading equipment specifications.
考试技巧
Milliwatts to watts = Divide by 1000. Remember: To convert milliwatts to watts, divide by 1,000. 500 mW ÷ 1000 = 0.5 W.
记忆口诀
**M**illiwatts **T**o **W**atts = **M**ove **T**hree **D**ecimal **P**laces **L**eft (think 'MTW = MTDPL' = Move Three Decimal Places Left, divide by 1000)
实际应用示例
Your handheld transceiver might consume 500 milliwatts (0.5 watts) when receiving. This is a very low power consumption, which is why handhelds can operate for many hours on a small battery. Understanding that 500 mW = 0.5 W helps you understand power consumption specifications and calculate battery life.
错误选项分析
Option A: Incorrect. 0.02 watts equals 20 milliwatts, not 500 milliwatts. You're off by a factor of 25. Option C: Incorrect. 5 watts equals 5,000 milliwatts, not 500 milliwatts. You multiplied instead of dividing. Option D: Incorrect. 50 watts equals 50,000 milliwatts, way too large. You're off by a factor of 100.
知识点
Power conversion, Milliwatts, Watts, Unit conversion
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.