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What really is happening inside a wire and inside battery when I connect one end of wire to the one terminal of battery but not the other (open circuit )?

Questions:

  1. If I connect to the '+' terminal does any electron (even one ) get sucked inside battery terminal or not? If not why so?

  2. If now, I connect wire's other distant end to another terminal (closed circuit ), what happens at starting? Which terminal will act first in drawing or supplying electrons. (I mean process of starting current).

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1st electron bounces out of -ve terminal but only moves the distance to > next electron in a chain reaction.

![enter image description here ref: http://web.engr.oregonstate.edu/~traylor/ece112/beamer_lectures/elect_flow_vs_conv_I.pdf

“The nice thing about standards is that there are so many of them to choose from.” ;)

Actually the electrons in conductors, don't get sucked. With a n EMF or electromotive force when they bounce around they bounce more in one direction like a fire-brigade analogy or a wave in a football stadium. Do people get sucked out of their seats?, when the hand "wave" of current flows in one direction.

Imagine a square wave doing this to electrons but far less motion creating little or no current but a voltage at the end of a wire.

Then with very high current density the electrons drift in one direction with AWG10 at 10 A flow about 3360 mm per hour versus the chain reaction of the wave bumping random electrons at the speed of light in the direction of flow.

Do the electrons move? no but maybe drift very slowly 0.000x [m/s]
Does the wave move? yes at the speed of light in a conductor surrounded by air or a vacuum \$3x10^8\$ m/s , yet only ~\$2x10^8\$ m/s surounded by plastic in coax or PCB epoxy with a ground plane.

  • due to electrons bumping each other opposite to the "Convention of flow" established by Franklin. But for logical reasons a +current down a resistor with 0V at bottom, creates a +voltage at top.

    Physic ref on drift

The rate of bounced charges, Q over time, t we call current I=dQ/dt but by convention we say +charge out of + terminal rather than -ve electrons out of negative terminal.

OK now for AC

In AC current, the electrons never move in a conductor, just the wave vibrates back and forth with zero resistance in a chain reaction of electrons in the conductor around the loop, but with some resistance in the load to accept power. The wave oscillates back and forth around the loop.

But for really long distances relative to the frequency and if the wave travels more than 10% of its wavelength then reflections may occur to reduce the amplitude, if the impedance is not matched. ( like a guitar string with one end fixed, the excitation reflects back 100% and oscillates when plucked. But if it had same resistance from source to string to termination, the 1st wave would not be reflected and ring. It would flow to the end and be absorbed by the load resistance for one-half cycle then repeat for the negative cycle, and repeat again. This is "Matched transmission line theory" used in RF where reflections can cause nulls. So for really long power transmission lines, they must compensate any effects from reflections by impedance matching with series or shunt caps or series or shunt reactors.

But with a skipping rope and two gnerating a circle, is like two AC generators at the same voltage but no energy transferred from one end to the other, except to overcome gravity and weight of the rope. So when current flows, there must be a phase, frequency or voltage difference at each end. ( then it is harder ( more energy needed to rotate the rope)

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  • \$\begingroup\$ I found above answer useful but I don't think there is explanation of my questions above . \$\endgroup\$ – Nanda Sinha Apr 8 '18 at 17:11
  • \$\begingroup\$ True I was expecting you think about your question with this awareness and try to answer yourself. This proves you understand it. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Apr 8 '18 at 17:19
  • \$\begingroup\$ Now sir I didn't understand your comment. Is your answer was really a solution to my questions ? \$\endgroup\$ – Nanda Sinha Apr 8 '18 at 17:29
  • \$\begingroup\$ YES but you are supposed to think about then it shows you understand. If others wish to tell the answer. will you understand? Do you understand how people create a wave in a stadium . Imagine they are electrons Do they get sucked out of their seats?No but the 1st leans toward next seat. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Apr 8 '18 at 17:34
  • \$\begingroup\$ But battery really inject electrons from one end and collect from another end (it really happens isn't it? not the same electron though) .I understand this but out of curiosity I am taking these questions. \$\endgroup\$ – Nanda Sinha Apr 8 '18 at 17:39
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  1. If I connect to the '+' terminal does any electron (even one ) get sucked inside battery terminal or not? If not why so?

Yes, this will happen. Which way it goes depends on the relative voltages of the wire and the '+' terminal before connection.

  1. If now, I connect wire's other distant end to another terminal (closed circuit ), what happens at starting? Which terminal will act first in drawing or supplying electrons. (I mean process of starting current).

When you connect the other end of the wire to another terminal so there is a circuit, current will start to flow. The process "starts" where you connect the wire, but the "information" about the connection propagates at near light speed.

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