0
\$\begingroup\$

To my knowledge, a voltage source just drive all free electrons of a conductor in a closed circuit to complete a loop (after reaching positive end.. Again to the negative end ... To repeat the cycle) Is that correct or wrong?? Moreover electric current is the quantity of charge passing through a cross sectional area per unit time.. I mean if current increases, how come the electrons quantity increase in a closed circuit conductor.... Correct me if I was wrong.... Thanks in advance

\$\endgroup\$
3
  • 3
    \$\begingroup\$ Do you have a specific question? \$\endgroup\$
    – Eugene Sh.
    Jul 16 '18 at 14:23
  • \$\begingroup\$ I mean if current increases, how come the electrons quantity increase current is expressed in charge per time unit (ex: Coulombs / second) and an electron has a fixed charge so one Coulomb contains a fixed number of electrons. If the current increases, there's more charge per second so that must mean more electrons per second. So it is true "be definition". \$\endgroup\$ Jul 16 '18 at 14:29
  • 2
    \$\begingroup\$ I think this question is asked at least every 6 months with a slight variation \$\endgroup\$
    – Voltage Spike
    Jul 16 '18 at 19:32
2
\$\begingroup\$

"how come the electrons quantity increase in a closed circuit conductor"

It is not the quantity of electrons in the conductor that changes, in fact that changes very little. As you said, it is (my emphasis)

"quantity of charge passing through a cross sectional area per unit (of) time"

In the water equivalent (which sort of works, but don't let yourself be carried away by it; it is just an analogy, not a reliable model) consider a water pump, with a hose connecting the output back to the input. Pump and hose are filled with water. The amount of water never changes, but when you crank up the pump, the water will circulate faster: more water passes through each cross-section of the hose per unit of time.

\$\endgroup\$
3
  • \$\begingroup\$ Thank you Wouter van Ooijen... Sir can u explain electrons returning to negative end from positive end ( in voltage source) to complete steady current in circuit loop \$\endgroup\$ Jul 16 '18 at 14:46
  • 1
    \$\begingroup\$ No, and generally it is beyond electronics how this is achieved. It is chemistry (for batteries) or physics (for photovoltaic cells and dynamo's/generators) or math (for ideal voltage sources). You don't need to know how an enigne works to drive a car. \$\endgroup\$ Jul 16 '18 at 15:00
  • \$\begingroup\$ @saisridatta The path for current is through the voltage source. So, the flowing charges don't just return to positive end, instead they penetrate through the voltage source. Their path is an endless loop, a closed circle, "Complete Circuit." \$\endgroup\$
    – wbeaty
    Jul 16 '18 at 20:17
0
\$\begingroup\$

Not necessarily. Voltage Source provides an Electric Field that travels through the conductor once it's switched on. This field when reaches a point it moves the electrons, but electrons don't need to travel all the way from + to -. Energy travels from + to -. Consider AC for example, electrons never leave their place, but voltage and energy travels from the generator thousands of miles away to your home.

\$\endgroup\$

Not the answer you're looking for? Browse other questions tagged or ask your own question.