2006-08-11 01:09:54 · 7 answers · asked by kamel a 1 in Science & Mathematics ➔ Physics
Because otherwise you could make a perpetual energy machine. Imagine going from A to B along one branch, and then from B back to A along another. The potential energy difference for this circuit would br e(V_AB+V_BA) and if V_BA isn't exactly -V_AB then you get extra energy. The electrical field is what is called "conservative." You can't get more energy out than what you put in.
2006-08-11 03:57:31 · answer #1 · answered by Benjamin N 4 · 0⤊ 0⤋
Voltage = electrostatic potential difference. Suppose point A is grounded and point B has an electrostatic potential of 5 volts greater than point A. Therefore the voltage between point A and point B is 5 volts. You can then connect as many circuits to point A and point B and the potential difference remains 5 volts. However, as you connect more circuits to the voltage source, you draw more current out of the voltage source. Batteries are essentially charged capacitors. They discharge as current is drawn out of the which means that the voltage across it decays exponentially.
Think of voltage as height. Ground is at sea level and the top of the cliff is X meters above sea level. No matter how many bridges we build from the top of the cliff to other points, the heght of the cliff remains X meters.
2006-08-11 08:18:07 · answer #2 · answered by Anonymous · 2⤊ 0⤋
Voltage mean energy per charge - is it measured in Joules/Coulomb (also known as Volts), so it is a measure for the mount of energy a unit of electrical charge looses by moving from one pole to the other.
Compare to the potential energy of an object in the gravitational field. If it's mass is m and the starting point of it's path is at a height h above its ending point, it's potential energy is mgh, where g is the gravitational acceleration. You may say that the "voltage" is gh.
If the object travels from the starting point to the end point, it's loss in potential energy is always mgh, no matter what path (="parallel circuit") it follows.
2006-08-11 08:20:36 · answer #3 · answered by helene_thygesen 4 · 0⤊ 0⤋
In a circuit, there're just a bunch of moving electrons, at the battery each electron is given a charge, measured in voltage. Wherever the electron goes, it still has the same voltage as the next.
The voltage is reduced at resistors.
2006-08-11 08:27:36 · answer #4 · answered by adklsjfklsdj 6 · 0⤊ 0⤋
in parallel circuits each member of the circuit is connected individually to the source of potential difference so the voltage is not divided.all positives are connected together and all the negatives are connected together
2006-08-11 08:15:53 · answer #5 · answered by raj 7 · 0⤊ 0⤋
because the wire that has no resistance u can consider as a dot.. so when the resistance are connected in parallel the wire that connect them can considered as a dot and has the same voltage..
2006-08-11 08:27:00 · answer #6 · answered by meshan_heek 2 · 0⤊ 0⤋
One side of each component is held at one potential and the other side of each component is at another potential. So the pd across each component is the same (ie the same voltage).
2006-08-11 10:53:01 · answer #7 · answered by hippoterry2005 3 · 0⤊ 0⤋