Electric Newb

Hey guys. I googled this cool text book and by association the forums too. I'm a total nut for anything electric.. I am trying to 'get inside' to understand them better and learn to work on and with them. I understand most of the basics so far but one thing is throwing me a loop. On this page, down near the bottom where it discusses breaks in a circuit it says, "the full voltage produced by the battery will be manifested across the break". My brain seems to knot up on that. The way I understand voltage is, the force pushing electrons along the circuit. If that is so how could there be voltage in a break where there is no flow at all? I have a ton of other questions too but, I'm going to wait until the book covers them before I start spouting them out. Thanks for taking the time to read my question and for any helpful advice.

~Matt

 

If there is no break in the circuit, then there would be no voltage drop in the conductor. Therefore, if you placed a volt meter on the conductor, you would read 0 volts. If you break (or open) the circuit, current will cease to flow, and if you placed a meter across that open, you would read the source voltage. So, what they mean by "full voltage...being manifested across the break" is that you will be able to measure the source voltage at the break (open).

Example: You have a light switch and it is in the on (closed) position. If you place a volt meter across the closed, energized switch you will read 0 volts, even though the light is on. When you turn the light off (open the switch), the same meter will now read what ever the source voltage is.

Why? Because current generally takes the shortest path available. In the example above, when the switch is closed, the switch is the shortest path for the current. When the switch is open, the meter leads and meter provide the shortest (and only) path for current. Though your light will not turn on with the meter across the open, you will only be able to measure the voltage with the switch open.

Hope this helped,...

 

Thanks you very much. That helped tremendously (or however its spelled). I think I understand it perfectly now. Volts are the measure of potential energy thus, you read 0 volts when the circuit is closed because all the energy is kinetic. Again thankyou very much.

 

full voltage drop across the line of break... both sides of the break have full voltage of source thats all it says..
once you get into cb's and fuses youi will see this again