- #1
kostoglotov
- 234
- 6
This isn't actually a homework problem, but it is an example in a my textbook that I have a question about...
imgur link: http://i.imgur.com/2OglMH4.png
Ok, I wanted to clarify some things. I understand that current flowing from a positive terminal to a negative terminal represents a positive voltage drop. I can see why the second voltage source (-8V) is a negative, since current is flowing against that voltage gradient within the component.
Two things
(1) the current is also flowing against the voltage gradient inside the 32V source, but the voltage is given as positive...is this because it is the dominant voltage source...so it represents not a voltage drop but a voltage rise, and as such, it is equivalent to a negative voltage drop...so a negative times a negative...?
(2) the resistors are passive elements, surely their polarities should be determined after we've figured out which way the current is flowing, no? Because the polarity of the bottom resistor should be reversed shouldn't it?
imgur link: http://i.imgur.com/2OglMH4.png
Ok, I wanted to clarify some things. I understand that current flowing from a positive terminal to a negative terminal represents a positive voltage drop. I can see why the second voltage source (-8V) is a negative, since current is flowing against that voltage gradient within the component.
Two things
(1) the current is also flowing against the voltage gradient inside the 32V source, but the voltage is given as positive...is this because it is the dominant voltage source...so it represents not a voltage drop but a voltage rise, and as such, it is equivalent to a negative voltage drop...so a negative times a negative...?
(2) the resistors are passive elements, surely their polarities should be determined after we've figured out which way the current is flowing, no? Because the polarity of the bottom resistor should be reversed shouldn't it?