I am trying very hard to understand voltage. I am a second year engineering student in a physics II class. I am having trouble grasping the concept of voltage. Could you guys please help me out with a few questions.
Please correct me if I am wrong, but isn't voltage the difference of two separate electric potentials?
If you were to measure the electric potential at a certain point, you'd get a certain value "x" in J/C... but what is that measuring? What does that scalar represent? If you were to put a one coulomb charge at that point you'd have "x" J. But since you only measured one point in space, what is that in reference to? It takes "x" amount of Joules to do what? Is it just saying that at that point, that charge would have that much potential energy?
I am also confused about voltage drop across a resistor. So if you were to hook up one lead of a voltmeter on one side of the resistor in a circuit and the other lead to the other side, and you get a reading of "x" volts. That voltage to my knowledge represents the difference between the electric potential on one side and the electric potential on the other side... the drop. So my question is if you were to just have a wire going from the positive terminal of the battery to the negative terminal of the battery, and then you measured the voltage across that, wouldn't it be zero? If not, why wouldn't the reading be zero, there is nothing in the circuit to drop the voltage, so it should remain the same and x volts minus x volts is zero.
But here's where I'm confused, I've seen videos of people measuring the voltage of the battery by connecting the voltmeter to each terminal of the battery and getting the reading, but why did they get a value and not zero, since the difference should be zero?
Also, why have I heard of voltage being "the force" that pushing electrons through a circuit, when voltage is not a force. Force is measured in Newtons, and voltage is Joules/Coulomb. So I can't grasp how voltage could "push" electrons, given the units voltage has.
And the last thing I don't understand is why the voltage drop across all the resistors in a circuit must always be zero. The idea that the voltage drops to zero across a 10 ohm resistor in one circuit, and also drops to zero across 2 different 10 ohm resistors in a different circuit is mind boggling to me.
I know this is a lot of questions, and the questions may be confusing, but it is hard for me to word questions when I don't know what I'm talking about.