Definition of electric current

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Electric current is defined as the time rate of change of charge, expressed as I=dQ/dt. In a steady flow scenario, such as a wire with a constant current, the number of charges entering a section equals the number exiting, but this does not imply that current is zero; rather, it indicates a steady flow of charge. The discussion clarifies that current density refers to the amount of charge per unit area or volume, while current itself measures the total charge passing through a cross-section over time. Therefore, even with a constant current density, the current can still be non-zero. Understanding these distinctions is crucial for grasping the concept of electric current.
aalnaif
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I'm confused by the definition of electric current. It is commonly defined as the time rate of change of charge (I=dQ/dt). However, considering a wire with a steady flow of electrons (a constant, non-zero current), wouldn't the number of charges entering a certain section of the wire equal the number of charges exiting from the other side of the section, such that dQ/dt=0?
 
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Suppose a general watching the troops saw 10 soldiers per second marching past.

This is and example of steady flow.

So he tells them to speed up and now 100 soldiers per second march past.

Again this is steady flow.

Flow of charge(s) is just like this.
 
Studiot is correct. Current is defined by the movement of charge. You are computing a difference which is more like the divergence of charge.
 
@aalnaif

Just to expand a bit on the answers others have given, what you described in your post would be a current density (i.e. current per unit area or volume), as opposed to the current. Your analysis is correct in that the current density in your example is not changing, however the current is clearly non-zero, as you yourself stated in the example.
 
see it is amount of charge passing through the given cross section in unit time . so if 10 C charge pases in i sec. then I= 10 A
 
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