Series Circuit Disconnected at Ammeter: Charge Flow?

[mich_v87]

Hey i have a little question to ask... when a series circuit is broken (disconnected) at the negative terminal of the ammeter , does the charge flow around the circuit until it gets to the end of the line at the ammeter and then stop ? or does it stop at the moment when it's broken?

 

[Tide]

The short answer is "yes, the current stops immediately!"

However, if you want to get into "overanalysis" mode then there is a little more to the story.

a) It takes a finite time for electrons in the circuit to "know" that there is no longer a potential difference. That information propagates at the speed of light and, typically, the time for the information to arrive is VERY small.

b) Once electrons are no longer subject to an accelerating potential, they are stopped, again almost immediately, because they collide with ions and give up their kinetic energy.

c) Even in the case of very low resistivity, any charge buildup will promptly be halted so that the conductor will become an equipotential.

 

[quicknote]

When a series circuit is disconnected at the negative terminal of the ammeter, the charge flow will stop at the moment the circuit is broken. This is because in a series circuit, the same current flows through all components, so when the circuit is broken, the flow of charge is interrupted and cannot continue. The charge does not continue to flow around the circuit until it reaches the end of the line at the ammeter because there is no complete path for the current to flow.