A measure of the rate at which electric charge is transported (especially through a circuit), it has units of charge/time.
Questions tagged [electric-current]
3332 questions
6
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3 answers
Is there no real current in AC?
I've always assumed AC to be just another kind of current. However, I've recently heard this statement:
There is no real current in AC, and we use the concept of current only to make understanding of AC easier.
Is this statement true? Why or why…
Myungjin Hyun
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5
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4 answers
Can we get shock by ionic current?
If two terminals of a battery are dipped in a ionic solution e.g. salt dissolved in water. Then if we put our hand in the solution then should we get shocked?
5
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1 answer
Surface current and current density
I want to know when I am asked to find the surface current density and the space current density what should I do? Also what is the difference between the surface and space current? Can the space current density help me to find the latter if I know…
Adam
- 495
4
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1 answer
Current is a scalar quantity, but how does it have a definite direction?
A scalar quantity is one which has magnitude but no direction.
A vector quantity is one which has both magnitude and direction.
The direction of current is opposite to the flow of electrons.
Electric current has both magnitude and direction so…
rishab bairagi
- 239
3
votes
3 answers
Why AC current lose less power over long distances than DC?
I was eager to know why AC current has a smaller power loss than DC over long distances. It depends on the fact that electrons aren't really going anywhere or it depends on other factors? Is there any physical explenation for this phenomenom?
Phys
- 57
3
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2 answers
How does DC current work in Cathodic Protection?
I have been trying to understand how does the DC current contirbute to the Cathodic Protection,but it doesn't seem very clear to me. I know that its a way to protect pipelines from corroding and that there are anodes and cathodes. By some means when…
user3052793
- 31
2
votes
2 answers
Movement of electrons without a battery
Let's assume we have a circuit without a battery,the wire in the circuit is not an ideal wire and the free electrons will have to do work to cross them. Now let's assume that as there is no battery connected electric potential at a point is $0$. As…
user264098
2
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1 answer
Magnet position for maximum voltage in an ac generator (Lenz's Law)
Animated gif credit
The picture above shows, that the voltage of a phase is greatest, when the magnet alligns with the coil of the phase. Why is that?
To my knowledge of lenz's law the voltage and induced current should be 0 when the magnet…
rogerg
- 33
2
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3 answers
Root mean square value for DC
The mean value of alternating current comes to be zero because of half of the cycle being positive while the other half negative. so, take the root means square value of Alternating current given by:
$I_{rms} = 0.707\times I_{max}$
But why do we…
Rafique
- 1,159
2
votes
1 answer
Ampere's Circuital law proof for closed circular loop
How do we prove the magnetic field for a circular loop is $\frac{\mu_0I}{2r}$ using Ampere's Circuital law
I proved it using Biot-Savart Law but i am getting $\mu_0I/2\pi r$ instead of $\frac{\mu_0I}{2r}$ while using Ampere's law.
Please help me…
Sayak Adak
- 31
2
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2 answers
Effect of Current on spring
When Current passes thru a spring , some books mention that it gets compressed.
However, I think due to the heating effect of current, molecules will increase kinetic energy and the spring should get elongated. What is the physical mechanism for the…
Nevil
- 21
2
votes
2 answers
What is the relation that links .m.f., current and electrons flow?
I'm asking this question because I'm a little confused about this topic. So, I know that the current (conventionally) in a circuit flows from the positive to the negative pole, and inside the cell current flows from the negative to the positive pole…
musicinmyheart
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2
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1 answer
Electric lamp and City electricity frequency
As far as I know the Public Power Supply frequency is 50hz.
Does it mean that lamps get on and off constantly?
Or they just remain on?
When you have some thing rotating it seems that light is not continuous as in certain speeds of rotation it looks…
Nemexia
- 199
2
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1 answer
Current divided into components like vectors
Current is a scalar quantity. In Watt-less current, we divide current into components like vectors. Moreover, when AC current passes through inductors or capacitors, we put a vector sign over current. Can anyone please elaborate?
2
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2 answers
why in the case of electric field the path of electrons is curved?
I was wondering ,that why in the presence of uniform electric field the electrons are moving in a curved path.
satyatech
- 125