The ohm (symbol: Ω) is the SI derived unit of electrical resistance, named after German physicist Georg Ohm. Various empirically derived standard units for electrical resistance were developed in connection with early telegraphy practice, and the British Association for the Advancement of Science proposed a unit derived from existing units of mass, length and time, and of a convenient scale for practical work as early as 1861. As of 2020, the definition of the ohm is expressed in terms of the quantum Hall effect.
There have been a few times in my career as a SW engineer when I have gone to the EE's on the project and they have been unable to answer my EE question. My thought is that if I post these problems on this message board, they might make it into the EE curriculum much to the advantage of newly...
Also would a passive filter add much resistance to the circuit and rob the speaker of power?
Here is the 2 way lowpass filter I was thinking of. I don't need 2 of these obviously but they seem to come as a pair.
https://www.amazon.com.au/dp/B07R613YSK/
When using the voltmeter and ammeter to investigate the circuit, it was found that the batter had a current of 0.67 A, the two 30 Ω bulbs had a current of 0.17 A, and the two 10 Ω bulbs had a current of 0.50 A. In terms of voltage, each bulb had a voltage of 5 V. When the switch was closed, the...
Hello,
Some trouble came up today with designing a 50 ohm system for a wireless powering project. I'd like to increase the frequency range for which my system impedance is 50 ohms in order to reduce power losses due to mismatch. I've simulated two RLC circuits in OrCAD SPICE to demonstrate my...
Summary: I know that the diffusion of charged particles in a magnetic field is described as a diffusion tensor with 3 components: Diff parallel to the field, perpendicular and anti-symmetric diffusion. Is this last one that I do not understand.
Dear community,
I am PhD candidate in...
Homework Statement
Hi all.
I need a bit help with the following.
Estimate the power developed in the 8 Ω speaker of the circuit of FIGURE 2 for a 1 kHz sinusoidal input signal of 100 mV peak. All capacitors may be assumed to act as a short circuit at the frequency of operation.
Compare your...
Today, I found that there exists something like a 0 ohm resistor:
https://www.electroncomponents.com/0-e-ohm-resistor-resistance-zero?filter_name=0%20ohm%20resistor
Don't look at the image in the page
I can simply connect two points in a circuit with a good quality copper wire, thereby...
Preface to thread: The multimeter is set to read resistance in all the scenarios I ask about in this message.
The word "COMP" in the ladder diagram stands for compressor motor.
The three letters underneath the capacitor are DRC, which stands for Dual Run Capacitor...
I'm trying to understand how I can mathematically describe a particular situation in order to calculate what I should expect to read on an oscilloscope.
Let's say I have a signal generator that is generating a 1MHz sinusoidal signal 1Vpp. The source impedance of the signal generator is 50ohm...
Hi guys , i am working in the automotive industry today i encountered a weird electrical issue and i am sure you guys have an explanation , i was using my multimeter to check continuity between different stuff , by mistake i put the leads on the car battery terminals i found the multimeter...
Homework Statement
Homework Equations
I = VR
Series = current the same, voltage different
Parallel = current different, voltage the sameThe Attempt at a Solution
Is the 1 ohm and 15 ohm parallel? I'm still learning to differentiate it.
If yes, then R = 15/16 ohm
Is the R series to 5ohm? If...
I want to know why in this problem in the solution, he disregarded the 1 ohm resistor and found the equivalent resistance of 6 and 3 ohms right away.
https://imgur.com/a/efG11
I don't understand how this is possible.
This is a rather large transformer in a stereo system amplifier. The transformer is a simple step-down with 120V mains primary to a center-tapped secondary providing both 38V and 76V.
According to ohm's law, at 120V this thing should draw about 85 amps...
Hi all,
We are planning to use RTD (Resistance temperature detectors) for our system which basically are temperature sensors that contain a resistor that changes resistance value as its temperature changes. The RTD can come in two nominal values: either 100 ohm or 1k ohm. Knowing that the RTD...
My curiosity was peaked when looking at this application circuit from linear:
http://cds.linear.com/image/Fig2_-_Wireless_Current_Sense_Circuit_Floats_with_Sense_Resistor.png
They put two 2M resistors in series instead of one 4M resistor. I've never really used anything bigger than 470K so I...
Homework Statement
We have 1Ω, 2Ω, 2Ω, 4Ω, 5Ω and 6Ω resistors. We have to make a circuit with all of them and total resistance must be 1 ohm.
Homework Equations
Parallel: 1/R1+1/R2=1/R
In series: R1+R2=R
The Attempt at a Solution
I have only made a circuit from 4 resistors:
1 ohm and 2 ohms...
Homework Statement
Find the current across 5 ohm resistor
Homework Equations
Superposition theorem. Other voltage sources become short circuit and current sources become open circuit.
Ohm's law. I = V / R
The Attempt at a Solution
Using superposition theorem, we get:
When only left side 10...
Homework Statement
The problem is to find the current in the 25 ohm resistor (left side)
http://imgur.com/a/luKCW
[Image inserted by moderator]
Homework Equations
KCL
KVL
ohms law (v=IR)
The Attempt at a Solution
My attempt at the solution was to add both power sources together (-5v(-5v...
Homework Statement
A circuit is setup with an ideal ammeter connected across the 4.0 ohm. What will the reading of the ammeter be?
2. The attempt at a solution
I am not sure whether the question is testing my understanding on how an ammeter should be connected in a circuit or about how to...
Homework Statement
I came across a question in my homework sheet where it give the unit of "L" in ohm when it supposed to be "Henry" (right?). So I just wondering, can ohm be converted into Henry?
Homework EquationsThe Attempt at a Solution
Hi.
I'm still confused about basic electricity. I have a USB power bank with two 1 A and one 2.1 A outputs. They all are specified with 5 V (all numbers from the manual, not measured myself).
I just can't bring this into agreement with Ohm's law U=RI. Shouldn't the resistance R only depend on...
*U=voltage
Homework Equations
U=IR (V=IR)
The Attempt at a Solution
200mA=0,2A --> 0,2*50=10V...? So because it's parallel the source should be 10V too right?
Homework Statement
A circuit is arranged like above.
To make the energy absorbed by the 6 ohm resistor every second is 1.5 J, voltage X should be ... Volt
Homework Equations
V = IRThe Attempt at a Solution
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I really have no idea.
I just know that it's kinda like wheatstone bridge and...
My local hobby store says no.
I want to draw a full 40 Amps from my power supply to play with a few formulas that give the magnetic field strength as a function of distance and current from a wire. The wire will be car battery cables. I have a calibrated Gauss meter for field measurements...
Hi,
I'm in a bind trying to determine how to handle impedance matching through a joint of copper wire sandwiched between two 50-ohm coaxial cables (the joint is an interface between atmosphere and a UHV system). There is a signal pulse with a rise time of 2 ns coming through one of the coaxial...
I feel that I don't understand how voltage works in a circuit. I understand voltage to be electric potential energy per unit charge (kq/r). In the case of a circuit, electrons flow from low potential to high potential. But I don't understand how resistors cause a voltage drop. Isn't voltage...
Homework Statement
Find the equivalent resistance
Homework Equations
Req(series) = R1 + R2...
Req(parallel)=(1/R1+1/R2...)^-1
The Attempt at a Solution
I'm having problems understanding how to simplify this circuit.
There should be parallel and series "loops" to simplify but I'm having...
Hello, my motherboard recently has stopped working, so I returned it to warrany, they fixed it, but after a few months the board broke again, but unfortunatly the warranty has ran out, so I'm attempting to fix it myself in the freetime :D So I have found a resistor on the motherboard, that looks...
Here is the problem: I have already lost the ability to get the correct answer for AI
Homework Statement
(a) What is the maximum potential difference that can be applied to the terminals a and b?
33.541
Which resistor will have the largest current? V
(b) For the voltage determined in part...
Hi, i didnt know where to put this question cos its kind of multitopic, here is why...
I am working on a better way to take mechanical energy from muscles, i made a teste bench for pedalling in very different ways, including traditional(circular) pedalling, the thing is. I am measuring the power...
I just need a clarification, I have been through a dozen www sites and cannot find an answer
they show how resistivity is worked out eg ...
the Ohm meter is usually shown with a "dot" between Ohm and metre
Is this the same as Ohm times metre ? or Ohms per metre or something else?
I would...
When and "for what purpose"/why are 1 mega ohm (1 MΩ) resistors used in filters, such as high pass filters? Is it with regards to electrostatic discharge or impedance matching?
What difference does it make, if I only use a 10 K ohm resistor, when the high pass frequency will be the same (by...
I have a 1K ohm potentiometer.(datasheet is attached below). My aim is to convert 12V to 5V,which I would then apply to power the Arduino microcontroller. I'm not quite sure if I CAN use the potentiometer I have ie T93 YA 1K 1035 to do this conversion.
The datasheet says that the maximum...
Hello All! I am having a rather difficult time locating the answer that I am seeking. What I am trying to determine is a little more understanding about resistance. I know that 1 Amp is coulombs per second, and that is 6.241×1018 electrons. I know that 1Ω is 1 Amp across 1 Volt. However what I...
Homework Statement
https://dl.dropbox.com/u/3405118/24-02-2013%2018-46-54.png
Find (a) the open-circuit voltage VL , and (b) the voltage across the 5 ohm load, by the following methods.
Method 1: Direct approach. First find the open circuit voltage by simple ‘potential divider’ approach
(but...
Homework Statement
Find the current through the 100 Ohm resistor:
http://imgur.com/sohdpyE
The Attempt at a Solution
So I was able to simplify the 100 and 500 resistors, as well as the 20, 20 and 10 series resistors, but I can't seem to discern at all whether any of the remaining ones...
Ok, let's say you have a 100v voltage supply and two 50 Ohm resistors in a series circuit. The total resistance is 100 Ohms, leading to a current of 1 amp.
Now my question is, what exactly is voltage drop? I know the voltage drop across each resistor is 50 volts. If we were to look at one of...
The is the Output circuit of a microphone I'm using to look at photoacoustic signal, is just an Op-Amp, connected to a high pass filter which is using a 30 Kohm resistor. Sadly, the signal the microphone gives is too strong for the lock-in I'm using to read the signal, and overloads it. I want...
Homework Statement
Design a suitable combination of resistors, capacitors, and/or inductors which has an equivalent impedance at ω=100 rad/s of 1Ω using at least one inductor.
Homework Equations
Zeq=ZR+ZL+ZC
ZR=R
ZL=jωL
ZC=-j/ωC
The Attempt at a Solution
I really am not sure how to start. I...
Homework Statement
I have two questions. Both questions are in the picture below. Dont mind my workings lol
http://img163.imageshack.us/img163/5680/scanpic0001qe.jpg
Ans to the 1st qn: C
The potential difference across the 3ohm resistor is zero. Thus, it can be considered that the 4ohm and...
Homework Statement
Find the current in the 10.0 ohm resistor in the drawing (V1 = 24.0 V and R1 = 15.0 Ohm)
Diagram: Homework Equations
Kirchoffs loop ruleThe Attempt at a Solution
well do i have to solve for both parts of the circuit if i just want to find the current at the 10.0 ohm...
Homework Statement
Use resistor simplification to find current across the 10ohm resistor
Homework Equations
V=ir p=vi
The Attempt at a Solution
Any help you can give me is much appreciated. When I did it i got down to a parallel circuit with a 30ohm and a 100ohm but didnt get a...
hello, good afternoon. I'm a little bit confused about the use of matching transformer. I made a 50 ohm tv antenna, and i connected it to a 50 ohm coaxial line. However, I've found out that for tv applications, 75 ohm coax should be used. my question is, if i will replace my 50 ohm coax, can i...
This will (maybe) be an easy question to answer. Here is my situation:
I have a 12v 200mA capacity transformer (wall wart) that I am using to power up a relay which takes about 5mA and has an input voltage range of 5-24v. Basically I need to burn off the other 185mA or so of the transformer's...
Homework Statement
a 500 ohm resister is fed by 120 Volt P-Peak ac source;How much heat does the resister dissipate if the signal is a sine wave or a square wave?
Homework Equations
The Attempt at a Solution
I'm not sure I understand this definition, it's written in a rather confusing manner...instead of saying how much ampere is being stopped from flowing, it tells us how much current is being produced!
That's a little confusing...I thought the definition for the resistance SI unit would be how...
In transformer when voltage increases on secondry coil then current decreases but i am confuse here that how ohm law is obeyed here.
as
V is d.proportiona to Current.
please advise...
Homework Statement
A current of 22 amperes flows in a heater coil whose resistance is 5 ohms. What E M F in volts is required?
Homework Equations
The Attempt at a Solution
Not quite sure where to begin. I'm thinking the internal resistance, R, is inherent w/the circuit so EMF...