Electromotive force Definition and 55 Threads

In an electric current there must be forces that push electrons in a general direction (current). My question is, what creates this force (electromotive force)? I assume that this force, that moves electrons, is created by a surplus of electrons in one area. Perhaps they move because the...

Hi everybody! I'm a physics-interested guy from Norway, who have a question. We don't have any such exellent forums in Norway. :-) I hope you understand my english by the way. :-) Homework Statement We have a battery with internal resistance 2 Ohm. The voltmeter shows 9 volt when no...

help me with this please... i just couldn't get it. 1) a complete circuit consists of a 12.0 V battery with a 4.50 ohm resistor and switch. the internal resistance of the battery is 0.30 ohms when switch is open. what does the voltmeter read when placed: a. across the terminal of the...

Here are my homework problems. I did most of them, but I don't understand how to do the others. 1. A rod of length 0.40 m moves in a magnetic field of magnitude B=1.2 T. The emf induced in the moving rod is found to be 2.40 V. a)what is the speed of the rod? b)if the total circuit...

If I have a rectangular coil with no current flowing on it traveling at a velovity v; and I have an infinetely long wire with a constante current i on the same plane of the rectangular coil which velocity v is perpendicular to the wire, is the lorenz force equal to zero because I have only...