Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [units]

A specified amount of a quantity (e.g. voltage, current, power, time, etc.) by comparison with which any other quantity of the same kind is measured or estimated. The standard system of units is the International System of Units (SI).

A specified amount of a quantity (e.g. voltage, current, power, time, etc.) by comparison with which any other quantity of the same kind is measured or estimated. The standard system of units is the International System of Units (SI).

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What kilogram is doing in volt unit definition?

My question is inspired by this: Why do farads multiplied by ohms produce a result that has a unit of seconds? I want to ask what kilogram is doing in this equation: $$\mathrm{V = \frac{kg \cdot m^2}{A \cdot s^3}}$$
Kamil
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What does BSC SQ mean?

I'm reading this DAC datasheet. The last page (p. 32) gives certain of the chip's dimensions, some in units of "BSC SQ". What does BSC SQ mean? Is it standard to express sizes in BSC SQ?
Randomblue
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Why is apparent power not measured in watts?

I'm studying circuit analysis. We are currently learning about AC circuits, particularly how power is calculated. I learned that there are four types of power: Complex, apparent, active and reactive, which makes sense, but I'm confused about the…
ShootinLemons
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What does the "proportional symbol" (∝) mean when used as a time unit prefix?

In several datasheets for electronic components, I have seen a ∝ symbol used as a prefix for a time unit, usually seconds, writing as ∝s. As far as I know ∝ is not a valid SI prefix, so what does it mean? What unit is ∝s? Comparing different…
Pep
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Is "p" ever used to abbreviate pi in formulas?

I keep running into formulas in datasheets and articles that appear to be abbreviating pi as 'p'. An example from Ask The Applications Engineer-25: Op Amps Driving Capacitive Loads shows "1/2p..." in many places when calculating frequencies of poles…
Ben Froelich
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Why is current (and not charge) an SI base unit?

Recently I've been wondering why the Ampere is an SI base unit and not the Coulomb (which is derived). I read this answer https://electronics.stackexchange.com/a/23456/16834 , but I'm not sure I'm understanding the discussion. To me it seems like…
hedgepig
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What is the physical significance of the unit ampere/meter in magnetics?

I'm having a hard time understanding what is the stuff this unit measures. I understand ampere, and I understand meter, and I understand per, but since ampere is a measure of current, I'm having difficulty understanding how this relates to…
Phil Frost
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Which is correct, kohm or kOhm?

Should the unit "Ohm" be capitalized or not? For example, "kOhm" versus "kohm" vs "kΩ", which is most correct?
Alex I
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Misconceptions about PID Controllers

I'm currently designing an equivalent of the mass-spring-dashpot system, and during the design phase I realized I don't fully understand how PID controllers physically work. Below is an image, the top half of which is the physical setup. There's a…
anonymouse
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dimensional analysis of the Shannon-Hartley theorem

In the infamous Shannon-Hartley theorem the bandwidth of the channel is measured in Hz (Hertz) but the channel capacity is measured in bps (bits per second). So, either I'm missing something obvious or there's a dimensional mismatch in the…
gpo
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PCB Layout: Reconciling metric and imperial measurement units

I am using Eagle CAD to lay out a BGA based PCB, for manufacture at Laen's prototyping service. One of the problems which I am having is that BGA parts are typically specified using metric units (for example the ball pitch is .8 mm), but that…
Zuofu
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Confused about MW to MWh conversion

I have various datasets of energy production in MW. I need to present everything in MWh. I need to know if my data is already by the hour (logging a value for each hour of each day of an entire year), if the sum of all those values in MW also equals…
Bex
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Confusion between MW and MWh

A 1MW power plant producing power constantly for 24 hours will produce 24 MWh a day. Is that right? If it is, I don't understand when it says, in http://www.beaconpower.com/files/Flywheel_FR-Fact-Sheet.pdf, that the 20MW energy storage plant can…
Eric
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What units are kpts?

I am parsing data from a Siglent SDS2000X oscilloscope. The first chunk (0x00 - 0x003) is for wave_length. The data sheet states that for arbitrary waveform generation, the wave length is "16 Kpts". What unit is Kpts? Kilo-Points? How would I…
Lorem Ipsum
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Convert VAh to kWh

Sorry, this might be a stupid question as I'm not an electrical person. I'm analyzing an electricity consumption dataset and the consumption is measured by apparent energy (VAh). How do I convert this VAh to kWh as normally seen on a power bill? Or…
foo
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