What is the nature of Electrical Ground.?

Question

What is the property of a grounded connection that makes electrons seek it? For example in a dc circuit if you physically ground a connection that will be the path that the electrons take ...why? Why not the positive termanal of a battery for example? What is Ground? In an automobile ground is the positive terminal of a battery...why does a physical connection to ground connect a circuit?

Answer 1

"Ground" is the reference point by which you measure all voltages. Voltage is the electric potential between TWO points. So you want to find the voltage of a single point, the best way would be to reference it to whatever point you chose to be your "ground." This way, your voltage measurements are consistent across the entire circuit.

Current does not necessarily always flow to ground. Current always moves from a higher voltage to a lower voltage. So if you have a point that has positive voltage, it will flow towards the ground node, since voltage of the ground node is 0 V. If you have a point with a negative voltage, current will flow from the ground to that point. NOTE: the direction of current is OPPOSITE the direction of electron flow.

You can set the positive battery terminal to ground, the circuit does not change, just your measurement of voltages. Let's use your example of a car battery. The voltage between the positive and negative terminals is 12 V. If you set the ground to be the negative terminal, then the voltage at the positive terminal is +12V and the voltage at the negative terminal is 0V. If you flip it so that the positive terminal is ground, then its voltage is now 0V and the negative terminal is at -12V.

Ground is simply a reference point by which you do voltage measurements across the circuit. Feel free to private message me if you have any more questions.

Answer 2

Electrical ground is commonly connected to the other pole of the voltage source. Electrons have to go there to replace the ones that are leaving (and so it's called a circuit). Electricity always takes the path of least resistance back to the source. Electrical grounds are the past of least resistance.

Tesla discovered that the dirt in the ground could be used as a return circuit ... so they only needed one wire to transport electricity in rural areas. That's why it's called "ground". Strange idea, wonder whatever made him think of trying it?

(There are some great Tesla sites on the net these days. Fascinating.)

Either pole of a battery could be defined as "ground". Some cars do it one way, some do it the other. Same with any other electronic circuit. It's usually a question of what makes the design easiest.

Answer 3

Ground is zero volts. The reason that electrons seek ground is because the negative terminal of the battery is usually connected to it (for safety reasons).

Actually, electrons do not seek ground; electrons leave the "ground" and flow into the positive terminal of the battery. The negative terminal of the battery is connected to the ground to replace the electrons that are lost to the positive terminal of the battery.

Answer 4

Ground = reference voltage called "zero", often the negative voltage of the power source.

When you "ground" a circuit you create a direct connection from a point of higher voltage to the zero voltage. Because there is a potential difference across this connection, a current will flow. That is not a special property of the ground.

If the positive terminal would be chosen to be the ground, all potentials in the circuit would be negative relative to it. There is nothing wrong with it, it is just not handy to work with.

Answer 5

"ground" in the DC sense is equivalent to "common"... i.e. you are using the entire chassis of a car to act as the (-) terminal to reduce the amount of wiring used... before the 70s, some british cars used a positive ground, just the opposite as what is common today... interesting, how the standard came to be that (-) is always "grounded"... there really is no reason for it!