# What is the GROUND?

#### beanryu

Joined Dec 9, 2005
2
What is a ground? What is its polarity? How does a current flow to the ground but not through your hand, since your hand is very conductive too.

If a capacitor and a battery is connected in series, is it true that there will be no current flow since the capacitor is an open circuit?

#### ahuebel

Joined Aug 22, 2005
19
What is a ground?
A ground in the sense you are speaking is a safety ground used to provide equipotential between something you may touch, and the ground you are already touching, in the event of a short. Another thing it often does it shunt surges so they dont pass current through your equipment. Another reason for a ground in a circuit, is to provide a reference point.
What is its polarity?
The ground typically has no charge to speak of, the soil is basically a medium and hopefully the location of the ground is far enough away from something that would complete a circuit, that the current is fully attenuated.
How does a current flow to the ground but not through your hand, since your hand is very conductive too.
A typical safety ground should have 5ohms of resistance or less. Your hands have kilo-ohms of resistance. There can still be enough current to cause severe harm or death even with a grounded circuit. http://www.allaboutcircuits.com/vol_1/chpt_3/4.html
If a capacitor and a battery is connected in series, is it true that there will be no current flow since the capacitor is an open circuit?

#### beanryu

Joined Dec 9, 2005
2
What is a reference point?... and why do we need to ground the ocilliscope?

Are you trying to tell me that electron flow through the capacitor through the electric field?

"Oddly enough, however, extra electrons can be "squeezed" into a conductor without a path to exit if an electric field is allowed to develop in space relative to another conductor."

According to the article "As the electric field is established by the applied voltage, extra free electrons are forced to collect on the negative conductor, while free electrons are "robbed" from the positive conductor. " does it mean that if i put to 2 wires that are connected to a battery and attach a plate to them, then place the plate very close together, then it will act like a capacitor.

One more question, if I connect batteries in a circuit, meaning the positive terminal to a negative terminal of another battery, the batteries would eventually heat up and burn right?