The resistors tag has no wiki summary.
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1answer
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heat energy and resistance of an elctric circuit
Very often it is said that "heat is developed" in a resistance when there is an electric current in it. But as far as I know heat is defined as a form of energy being transferred due to difference in ...
3
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2answers
39 views
How to calculate resistance of bunches of wires
I figure that the resistance of multiple wires would work just like adding in parallel, a bunch of wires that is. But couldn't any wire just be viewed as a bunch of wires, albeit small ones? I know ...
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0answers
69 views
How does current flow in a irregularly shaped heterogeneous resistor?
The motivation for my question is understanding how electricity gets through your skin as opposed to running along it, and how the presence of things like water on the skin affect the relative ...
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2answers
28 views
Question regarding inverse relation of resistance with area of cross section
It is said that resistance is inversely proportional to area of cross section. But greater area will have greater electric flux, and greater electric flux will have greater magnetic flux, and greater ...
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2answers
54 views
Thevenin equivalent of a circuit
Ok so I can't post the image of my question and my attempt at it,
so I would like to ask, if anyone knows the steps to simplifying a circuit with dependent current sources, independent voltage ...
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2answers
54 views
How does symmetry allow a rapid determination of the current between $A$ and $B$?
The following was originally given to me as a homework question at
my physics 2 course:
Consider the following circuit
The difference of potentials between the point $V_{1}$and the ...
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1answer
30 views
Would the empirical behavior of a simple circuit match my model of it?
I have a practical problem in E&M which has baffled me and and my electrician. The copper water pipes in my house are carrying a current of small potential (~1V) AC current. Here is my ...
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3answers
70 views
Which quantity gives the resistance of a component?
In a current vs potential difference graph, we can obtain the value of the resistance of the component. There are books that say gradient-inverse is the resistance and also books that say the value of ...
4
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1answer
140 views
Does rubber insulate lightning more effectively than air?
Last week, an Ars Technica writer was struck by lightning. He says that the 911 operators were concerned about whether or not he was wearing shoes at the time, but he didn't think it would make much ...
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2answers
58 views
Equivalent RC circuit to a RRC circuit?
I'm in doubt about a situation that I've seen sometimes: imagine we have a resistor in parallel with a resistor and a capacitor in series. Since I don't know how to generate figures of circuits to ...
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0answers
29 views
Calculate the electric current in the given circuit when (a) Key K is open [closed]
Calculate the electric current in the given circuit when (a) Key K is open.
(b) Key K is closed.
!]each resistors of 6 ohm 1
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1answer
42 views
Resistance of a copper wire [closed]
Resistance of a copper wire is 20ohm. If the diameter of the wire is 5mm and length 1ohm. Find the resistivity of the copper.
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4answers
158 views
Resistors in Parallel
From my book:
"A length of wire is cut into five equal pieces. The five pieces are then connected in parallel, with the resulting resistance being 2.00 Ω. What was the resistance of the ...
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1answer
28 views
Confused on Calculating Resistance Distance Matrix
I am trying to create a computer program to compute the equivalent resistance over any points on any rectangular set of resistors (all with a resistance of 1 ohm). It seems that the resistance ...
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0answers
66 views
Is this series or parallel? [closed]
How do you find I? and please explain which resistors are in parallel and which are in series? ("M" and ">" are resistors)
...
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2answers
431 views
Capacitors and resistor in series and in parallel [closed]
In this circuit, are $R_1$ and $C_1$ in parallel and $C_2$ and $R_2$ in series?
I have think that the currents that flows trought $R_1$ isn't the same that flows trought $C_1$ so, $R_1$ and $C_1$ ...
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1answer
121 views
Calculate Capacitance in Series AC Circuits?
I'm supposed to calculate the capacitance of an unknown capacitor in series, but I'm not sure exactly which equation to use.
I know the voltage across the resistor (Vr), voltage across the capacitor ...
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3answers
175 views
How exactly does a resistance reduce current?
I've heard that resistors are used to decrease current to a particular appliance, such as in the regulator of a fan. However, I've also heard that the total current in a circuit is always the same- in ...
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0answers
21 views
Carbon resistor [closed]
a carbon resistor is used as a thermometer on a water day when the temperature is 10 degree Celsius the resistance of the carbon resistor is 270 ohms what is the temperature on a spring day when the ...
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1answer
64 views
how to find the diameter of this fuse? [closed]
A fuse blows if the current exceeds 1.0 A. It is made of material that melts at a current density
of 620A/cm2. What is the diameter of the wire, assumed to have a circular profile, in the
fuse?
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6answers
1k views
Parallel circuits - Overall resistance decreases with additional resistor [closed]
Let's say that there is a parallel circuit with two identical resistors in parallel with each other. If a third resistor, identical to the other two, is added in parallel with the first two, the ...
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9answers
1k views
I don't understand what we really mean by voltage drop
This post is my best effort to seek assistance on a topic which is quite vague to me, so that I am struggling to formulate my questions. I hope that someone will be able to figure out what it is I'm ...
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1answer
567 views
Relationship between resistance and voltage drop
In a series or parallel circuit, if two bulbs have the same resistance, do they have the same voltage drops? The problem I am asking about is below. Do A, B, and C have the same voltage drops since ...
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2answers
912 views
Physical interpretation of y-intercept in a Current vs Voltage graph
So I collected current and voltage data from a simple circuit with a power source and a resistor, using a multimeter. I created a graph for this data using excel and got the y-intercept (which is ...
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1answer
112 views
Cable TV version of infinite ladder network [closed]
This is a problem in a college physics textbook, and its bugging me that I can't get it.
The figure shows a circuit model for the transmission of an electrical signal, such as cable TV, to a large ...
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3answers
189 views
kirchhoff's law.Simple question [closed]
So far I calculated total resistance and it is 4.66 ohms and there is 12 volt voltage across them, what is the best way or HOW to calculate current for each resistor ?
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2answers
804 views
Ohmic and Non-Ohmic devices
Why do some conductors follow Ohm's law and some do not? Isn't there any universal law that can explain the flow of current?
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0answers
368 views
How to find the equivalent resistance for the following circuit? [closed]
How do you find the equivalent resistance for the above circuit, if current is entering via A and leaving via C? Can it be done by treating it like a wheatstone bridge?
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1answer
236 views
Resistance of Light Dependent Resistor (LDR)
Is there a mathematical expression relating the resistance of Light Dependent Resistor (LDR) with light intensity?
7
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1answer
382 views
Resistance between two points in an infinite metal sphere/cube
Let's imagine that we have a tridimensional metal object of infinite size, and decide to calculate the resistance between two arbitrary points. How would we go about doing this?
I have thought of two ...
2
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1answer
390 views
Effective resistance of inductor
In a lab experiment, we connected a simple circuit: an AC voltage source, connected (in series) to a variable resistor and an inductor. We measured the current in the circuit, and the voltage that ...
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1answer
156 views
How do I solve the current of this resistor using Maxwell's Current Theorem?
I've been trying to solve this using the method the prof. taught us, and I happen to know the answer but I can't reach it no matter how many times I've tried. The circuit in question is below:
I am ...
2
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2answers
191 views
Is equivalent resistance always lower if we add a resistor to a passive electronic circuit?
How to prove that equivalent resistance of any passive network is always lower if we add a resistor between arbitrary two nodes?
Note that this is not necessarily a parallel circuit, 2 nodes that we ...
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2answers
819 views
Basic questions about voltage drop in DC circuit
I understand all the concepts of what voltage is using all the analogies but some things related to the drop of voltage across a circuit confuses me.
If I had a short circuit and attached a ...
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2answers
734 views
Wheatstone bridge galvanometer error
We had to measure the resistance of $R_x$, we balanced the Wheatstone bridge and did calculations. My question is: we didn't include galvanometer error into calculations. Why is that? I read that it's ...
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1answer
193 views
What does a positive gradient on a graph of V plotted against I mean in terms of EMF and internal resistance?
According to the equation $V = E-Ir$, the gradient of a graph of $V$ against $I$ should be $-r$ (internal resistance) and the Y intercept should be the EMF. Am I right?
In an experiment I used a ...
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3answers
2k views
Finding current using EMF & internal resistance
What exactly is the difference between internal resistance and resistance?
This came up in the context of a homework problem I have been given:
The circuit shown in the figure contains two ...
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0answers
58 views
Resistor branding color. [closed]
If I have a resistor with 100 volts applied to it with a resistance of 100 $\Omega$, then the resistor would dissipate 100W. What is the color branding?
My first thought, following the table was, 1 ...
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3answers
106 views
Why is current not 0 in a regular resistor - battery circuit immediately after you closed a circuit?
In regular open circuits with either a capacitor or inductor element, (when capacitor is uncharged) with a battery, when a switch is closed to complete the circuit the current is said to be 0 because ...
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1answer
65 views
Is Joule heating only between charged particles?
The Wikipedia page for Joule heating explains
"It is now known that Joule heating is caused by interactions between the moving particles that form the current (usually, but not always, electrons) and ...
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1answer
317 views
Non-conservative Electric Field
I was watching this video from Walter Lewin and while watching these two videos, I noticed there is a "contradiction" in what he is doing. All links direct you exactly to where he begins, so you don't ...
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2answers
304 views
Voltage and resistance in series connection
In a series connection with n elements it is true that (voltage):
$$V = V_1 + V_2 + ... +V_n$$
and (resistance):
$$R = R_1 + R_2 + ... +R_n$$
If I know one of these I can infer the other. But is ...
5
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2answers
176 views
Modeling stochastic process with frequency-dependent power spectrum
I'm trying to model of Johnson-Nyquist noise propagation in a nonlinear circuit. An ideal (linear) resistor can be modeled very nicely by the Fokker-Planck equation (equivalently, the drift-diffusion ...
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2answers
1k views
RC circuit theory and voltage in the capacitor vs Ohm's Law
Consider a simple series RC circuit at steady state (capacitor is full).
I've been told that once the capacitor is full we can literally "cut" the circuit because no current can flow.
That ...
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2answers
172 views
Fundamentality of voltage to current
From Ohm's Law :
Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points.
I would like to know if ...
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3answers
596 views
Why does the potential drop across a battery and resistor equal the emf of the battery?
In this diagram you can see the potential difference across the battery and resistor is the same as the pd created by the battery (the battery and resistor are representing a battery with internal ...
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3answers
1k views
Is it possible to mathematically derive the formula for resistance?
Resistance is given by $\rho L/A$, where $\rho$ is the material constant, $L$ is the length, and $A$ is the area.
Is there any way that this can be derived mathematically, or is the only way ...
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1answer
1k views
What defines the brightness of a bulb?
So I have a question. There are three identical bulbs, 2 of them are connected in parallel and the third is basically in series, on the same circuit. If the one of the lamps in parallel breaks, what ...
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4answers
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Resistor circuit that isn't parallel or series
What's the equivalent resistance in this circuit (between points A and B)?
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1answer
211 views
what is the proper way to connect two light bulbs in a circuit? in series or parallel?
What is the proper way to connect two light bulbs in a circuit? in series or in parallel and why?
My thought is that it's better to hook them in parallel, since if we take into account Ohm's Law, the ...
