How can i put the polaritiy of E thevenin's ?

[bibo_dvd]

Hello guys ..

i need your help with something

in this photo i understand the way to calculate R thevenin's and the way to calculate E thevenin's

but i couldn't understand

why did we put the polarity in this way ??

i mean why can't we put switch the polarity of the battery ??

thanks guys

 

[gneill]

why did we put the polarity in this way ??

Because solving the potential dividers shows that Vb is greater (more positive) than Va.

i mean why can't we put switch the polarity of the battery ??

If you want to turn the battery symbol around you can do so by specifying the battery voltage to be -6V rather than +6V. Technically this is allowed, but it may bother some who insist that a battery's positive terminal really should be positive with respect to its negative terminal

 

[bibo_dvd]

okay that's mean that we can turn the symbol of the battery if we turned "a" and "b" in the other side ??
i mean if we put b in the upper right side and a in the lower right side ?? :)

 

[gneill]

okay that's mean that we can turn the symbol of the battery if we turned "a" and "b" in the other side ??
i mean if we put b in the upper right side and a in the lower right side ?? :)

Sure, if you also move the ground symbol to the top so it stays connected to b.

 

[rezeew]

First of all, it's great that you are seeking to understand the concept of E Thevenin's and its polarity. In order to answer your question, let's first review what E Thevenin's represents. E Thevenin's is the voltage that would be measured across the output terminals of a circuit when all the internal sources (such as batteries) are replaced with their internal resistances. This is known as the Thevenin equivalent circuit, which is used to simplify complex circuits into a single voltage source and a single resistance.

Now, to address your question about why we can't switch the polarity of the battery in the Thevenin equivalent circuit, it is important to understand that the polarity of a voltage source determines the direction of current flow in a circuit. In the Thevenin equivalent circuit, the polarity of E Thevenin's is chosen in a way that it aligns with the original polarity of the voltage source in the original circuit. This ensures that the direction of current flow remains the same in both circuits.

If we were to switch the polarity of the battery in the Thevenin equivalent circuit, it would result in a different direction of current flow compared to the original circuit. This would lead to incorrect calculations and potentially inaccurate results. Therefore, it is important to keep the polarity consistent in both circuits when determining E Thevenin's.

I hope this explanation helps you understand the importance of polarity in the Thevenin equivalent circuit. Keep up the curiosity and keep asking questions! That's what science is all about.