Charging ObjectsSNC1P

Mr. M.Couturier

Charging ObjectsRecall the that electrons move according to

the Law of Electric Charges.Like charges repelOpposite charges attract

Charging ObjectsChallenge: What happens when a positively

charged object approaches a neutral object?http://physics.weber.edu/amiri/director/dcrfil

es/electricity/pithBallS.dcr

Charging ObjectsOne way to charge a neutral object is

through INDUCTION. This method implies bringing a charged object close to a neutral object (see previous notes) such that the electrons from the neutral object will move away from a negatively charged object or move toward a positively charged object.

Charging ObjectsAn object can be permanently charged by

induction by grounding the object. If a negatively charged object and a neutral pith ball are brought near (but do not touch), then the electrons in the pith ball are repelled by the charged object.

If you then ground the negative side of the pith ball, then the pith ball will become positive (because the electrons have flowed out of the pith ball).

Charging ObjectsCharging by induction always results in two

objects with opposite charges.

Charging ObjectsAnother way of charging objects is by

friction. Recall the electrostatic series. Here we have two neutral objects rubbing against each other such that electrons flow from the object that has the weakest desire to keep the electrons to the one that has the strongest desire.Why do planes have a cable attached to the

ground after they land?Why do fuel trucks have a cable or chain

touching the ground when they refuel a service station?

Charging ObjectsAnother way of charging objects is by conduction.

In this method a charged object comes in contact with a neutral object such that a balance is created. The electrons will flow from the object with an abundance of electrons until both objects have the same charge.

However, this method does not have to contain a neutral object. Two charged objects can come into contact such that the object’s electrons with the most electrons will flow into the object with the lesser quantity of electrons. It does not imply that it will neutralize the two objects (but it could).

Charging Objects

Charging Objects

Charging Objectshttp://www.youtube.com/watch?v=-JsVZwc1d

Oo&p=56BD404224912808&playnext=1&index=55