All Questions
Tagged with electric-circuits conventions
65
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Why does current lag behind voltage by 90° in an inductive circuit?
We can easily prove this with KVL, a little bit calculus, and trigonometry.
We get voltage as a sine function and current as a cosine function. Then we apply 'Add sugar to coffee' and get that current ...
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Why something connected to the ground has 0 potential?
I'm studying the concept of grounding of neutral wire in AC. I have done an extensive research on the internet to answer the question "Why the neutral wire has 0 potential ?". The answer is ...
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Confused about sign of mutually induced EMF when applying KVL
Suppose I have several circuits with inductors like so:
and I want to find the current $ i_1, i_2, i_3 $ in each circuit. I will use Faraday's law to find the induced EMF and then use Kirchhoff's ...
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Reference point of potential in case of a battery
When we define electric potential of a charge,we need to take a charged body as a reference and then we bring the test charge to calculate the electric potential. Now,electric potential energy is ...
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The limitations of passive sign convention in circuits
Passive sign convention means choosing an arbitraty current direction, then assuming that current always enters the positive terminal and flows out of the negative terminal of an element. Then the ...
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What is the generally accepted convention for potential difference $V_{AB}$? $V_A - V_B$ or $V_B - V_A$?
I already asked the question very clearly in the topic, so I will use this place to explain the context for which I present this question.
Normally, since I have been doing electrostatics, I have ...
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Earthing and Current flow
I have been doing problems based on earthing of a circuit but I have never understood as to why earthing(just a single point) doesn't affect the current flow.
I'm confused because if we have a cell ...
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Is it possible to have positive current coming from ground?
Is it possible to have positive current coming from ground?
This is only in physics land and ignores all real-world situations.
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How does Neutral Wire has lower potential than Live Wire?
This is my current(and most probably very incorrect) picture of how electricity comes in my house.
What I think of this picture is that, the transformer produces current in my house circuit (by ...
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Current sign convention RC and LC circuits
When deriving the equations for RC and LC circuits we substitute the current in the circuit with the time derivative of the charge on the capacitor. However, when I think about it, the rate at which ...
user345007
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Is voltage the integral of electric field or energy per unit charge? [closed]
See this video on the debate about the definition of Kirchoff's voltage law. See around 8:15. The difference in views seems to hinge on the definition of voltage.
In one case voltage is defined as
$$
...
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Can current also flow from low potential to high potential?
I understand that current flows from high potential to low potential.
As you can see in the picture, the top of the circuit has a potential 2V higher than the bottom.
However, since the current is ...
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Why am I getting negative current on the right loop of the Kirchhoff's circuit?
I have the above circuit and I calculated that the:
left loop = I1(Rc+4) - I2(Rc)=12
right loop = I1(Rc) - I2(Rc+3) = 5
I then generated numbers from 0 to 5 ohms with stepsize 0.1.
After replacing ...
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How do I know if the $120\rm\:V_{ac}$ is the rms value?
This is one of the questions in one of the books I am reading.
An incandescent lamp, rated at 100 watts, gives a certain amount of light when placed across the $120\rm\:V_{ac}$ power line. Would the ...
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Negative reading in voltmeter
Why does the voltmeter shows negative reading when connected in reverse order? What does it mean by negative voltage? Should we say voltage drop across $R2$ is $+12V$ or $-12V$? How to apply Kirchoff'...
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