Question based on a video (battery and voltage)

Thread starter gracy
Start date Feb 9, 2016
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Video Voltage

AI Thread Summary

The discussion revolves around the generation of potential difference in circuits without a visible battery or voltage source, emphasizing that charged capacitors can create voltage. Participants clarify that the potential difference in the circuit is due to the voltage across the charged capacitors, which may have been charged initially by a battery. Questions arise about the equivalence of potential across individual capacitors and their equivalent capacitance, with consensus that for parallel capacitors, the potential difference remains the same regardless of the initial charging method. The conversation also touches on the quality of educational videos, with differing opinions on their effectiveness and presentation style. Ultimately, the focus remains on understanding the principles of capacitance and voltage in circuits.

Feb 13, 2016

SammyS

Staff Emeritus

Science Advisor

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gracy said:

When I thought it is ##V_+## - ##V_-##

By ##V_+## I mean potential at either x or y whichever is at greater (positive potential ).

(##Q_1## - ##Q_2##)/(##C_1## + ##C_2## )This formula just gives potential difference and does not specify anything about which point is at greater potential.This is what thought.

First, think.

The above formula does specify which is at higher potential.
If ##\ Q_1< Q_2 \,,\ ## then ##\ Q_1- Q_2 \ ## and ##\ V_x- V_y \ ## are negative meaning V_y becomes the V₊.

I wrote there will be potential different between points x and y given by (##Q_1## - ##Q_2##)/(##C_1## + ##C_2## ) because at that time I knew x is at greater potential.