The prefix "milli" means "one thousandth", so to convert from amperes to milliamperes multiply by 1,000 (move the decimal point three places to the right).

\[1.5 \times 1{,}000 = 1{,}500\]

So 1.5 amperes equals 1,500 milliamperes.

Memory aids:

• Move the decimal point three places to the right to go from amperes to milliamperes (multiply by 1,000).
• A quick check: to convert milliamps to amps, change the comma (thousands separator) to a decimal point. For example, 1,500 mA = 1.500 A.

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Convert hertz to kilohertz by remembering that 1 kHz = 1,000 Hz. Dividing the given frequency by 1,000 gives the value in kilohertz:

1,500,000 Hz ÷ 1,000 = 1,500 kHz

You can also express the frequency in megahertz: 1,500,000 Hz ÷ 1,000,000 = 1.5 MHz. A common mistake is to read 1,500,000 Hz as 1,500 MHz, but 1,500 MHz would be 1,500,000,000 Hz (one thousand times larger).

Memory aids:

• kilo (k) = 1,000; move the decimal 3 places left to go from Hz to kHz
• mega (M) = 1,000,000; move the decimal 6 places left to go from Hz to MHz
• To go from Hz to kHz divide by 1,000; to go to MHz divide by 1,000,000

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The prefix "kilo" (used in metric units) means "thousand." Therefore, a kilovolt is equal to one thousand volts.

Memory aids:

• kilo = 10^3 = 1,000
• Examples: 1 kilometer = 1,000 meters; 1 kilogram = 1,000 grams
• Reference: http://en.wikipedia.org/wiki/Kilo-

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micro is a prefix in the metric system meaning "one-millionth". Thus, a microvolt is one millionth (1/1,000,000) of a volt.

One one-thousandth of a volt is denoted with the milli prefix (a millivolt).

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1000 milliwatts = 1 watt. Therefore 500 milliwatts = 500 / 1000 = 0.5 watts.

Memory aids:

• The prefix "milli-" means one thousandth, so 1000 milliwatts = 1 watt.
• Think in terms of dividing by 1000 to convert milliwatts to watts.

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A milliampere (mA) is one thousandth of an ampere (A). To convert milliamperes to amperes, divide by 1000.

3000 milliamperes ÷ 1000 = 3 amperes.

Therefore, 3000 mA equals 3 A.

Memory aids:

• "milli" means 1/1000 (10⁻³).
• 1000 mA = 1 A, so 3000 mA = 3 A.
• To convert mA to A, move the decimal point three places to the left.

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1 MHz equals 1,000 kHz, so to convert megahertz to kilohertz multiply by 1,000.

Using the value given: 3.525 MHz × 1,000 = 3525 kHz.

You can show the unit cancellation explicitly:

(\dfrac{3.525\ \text{MHz} \times 1000\ \text{kHz}}{1\ \text{MHz}} = 3525\ \text{kHz})

Because the fraction (\dfrac{1000\ \text{kHz}}{1\ \text{MHz}}) equals 1, the numeric value is unchanged except for the unit conversion.

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Convert between metric prefixes for capacitance. Working stepwise: 1 microfarad (μF) = 1,000 nanofarads (nF), and 1 nanofarad = 1,000 picofarads (pF). So 1,000,000 picofarads = 1,000 nanofarads = 1 microfarad.

Using decimals: 1,000,000 pF × 1×10^-12 F/pF = 1×10^-6 F, which is 1 μF.

Using exponents: 10^6 pF = 10^6 × 10^-12 F = 10^(6−12) F = 10^-6 F = 1 μF.

Therefore 1,000,000 picofarads equals 1 microfarad.

Memory aids:

• Every step between common metric prefixes (milli → micro → nano → pico) changes by a factor of 1,000.
• You only have to remember that every metric prefix moves by three zeros.
• A simple sheet helps: place three zeros under each prefix so you can read off that 1,000,000 pF = 1 μF.

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Doubling power corresponds to an increase of about 3 dB. Going from 5 watts to 10 watts is exactly a doubling of power, so the change is approximately +3 dB.

You can also use the decibel formula for power: L(dB) = 10 × log10(P1 / P0). For this case:

10 × log10(10 / 5) = 10 × log10(2) ≈ 3.01 dB

As a check, four times the power is about 6 dB (two doublings), and halving the power is about −3 dB.

Memory aids:

• +3 dB ≈ double the power; −3 dB ≈ half the power
• +6 dB ≈ four times the power (two doublings)
• Use L(dB) = 10 × log10(P1/P0) for exact calculations

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Decibels measure power ratios on a logarithmic scale. A change of +3 dB corresponds to a doubling of power, and a change of -3 dB corresponds to halving the power. Going from 12 watts to 3 watts is a reduction to one quarter of the original power (3 = 12 ÷ 4). One quarter is two successive halvings, so the total change is -3 dB + -3 dB = -6 dB.

You can also use the formula for power level change in decibels:

L_db = 10 × log10(P_new / P_old)

For this case: 10 × log10(3 / 12) = 10 × log10(1/4) ≈ 10 × (-0.60206) ≈ -6.02 dB, which is approximately -6 dB.

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The decibel change for a power ratio is given by the formula:

\[L_{dB} = 10 \times \log_{10}\left(\frac{P_1}{P_0}\right)\]

Here P1 is the new power (200 W) and P0 is the original power (20 W). So:

\[L_{dB} = 10 \times \log_{10}\left(\frac{200}{20}\right) = 10 \times \log_{10}(10) = 10 \times 1 = 10\;dB.\]

Thus the power increase from 20 watts to 200 watts corresponds to a 10 dB increase.

Memory aids:

• 10 dB corresponds to a 10× change in power.
• Every +3 dB approximately doubles the power (and −3 dB halves it).
• Example doubling steps from 20 W: 3 dB → 40 W, 6 dB → 80 W, 9 dB → 160 W, 12 dB → 320 W.

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To convert kilohertz (kHz) to megahertz (MHz), move the decimal point three places to the left (because 1 MHz = 1000 kHz).

With 28,400 kHz the decimal point is assumed to be at the end: 28400. kHz. Moving that decimal three places left puts it between the 28 and the 400, giving 28.400 MHz.

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One gigahertz (GHz) equals 1000 megahertz (MHz). Converting MHz to GHz means dividing by 1000.

Dividing 2425 MHz by 1000 gives 2425 ÷ 1000 = 2.425 GHz, so the frequency is 2.425 GHz.

Memory aids:

• Move the decimal point three places to the left to convert MHz to GHz.
• Remember 1 GHz = 1000 MHz.

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