2. Charging by Friction, Contact, Induction.notebook

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November 08, 2015

Charging by Friction

Charging by friction produces many of the same effects produced by static electricity.

Examples: Drying clothes in a dryer- The tumbling motion is kind of a rubbing action Walking across a carpet- The friction between the carpet and persons shoes produces a charge on both the person and the carpet.

Rubbing a comb through your hair- The comb strips electrons from your hair and becomes more negative while your hair will become more positive

The electrostatic series is a list to determine the kind of electric charge produced on each substance when any two substances on the list are rubbed together.

2. Charging by Friction, Contact, Induction.notebook

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November 08, 2015

Charge by Contact

A single spark produced by a charge transferred by contact can cause dangerous fires and explosions.

When charging by contact occurs, one object is already electrically charged. The other object may or may not be charged as well. The important thing to remember is that for charge by contact to occur, there has to be a difference in the amount of charge already on the two objects.

*Hand touching door-handle example*

2. Charging by Friction, Contact, Induction.notebook

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November 08, 2015

Charge by Induction

For this type of electric charge to occur, there doesn‛t actually have to be any contact between either object.

Remember: ANY neutrally charged object that comes in contact with a charged object will be attracted to that object. The same works for induction, except they don‛t touch.

Example: The dust particleIf it comes by, but does not touch, a charged particle, it will push the opposite charge towards the side nearest the charged particle. This will mean that one side of the dust particle will be negatively charged, while the other side will be positively charged.

+ + + + --- -

+ + + + + +

------

Dust particle with evenly spread out charges

Charged substance

+ + + + +

+

- --- --

+ + + + ----

This charging effect is known as induced charge separation.

If it has nowhere to go (neutral object not touching anything), the charge will evenly spread back out over the neutral object when the charged object is removed.

2. Charging by Friction, Contact, Induction.notebook

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November 08, 2015

InsulatorsAn electrical insulator is a substance in which electrons cannot move freely from atom to atom.

If atoms of an insulator build up a positive or negative charge, they stay on that atom and attract other neutral or oppositely charged particles.

Examples: wood, paper, plastic, rubber, silk

2. Charging by Friction, Contact, Induction.notebook

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November 08, 2015

Conductors

A conductor is a substance in which electrons can move freely from one atom to another.

Examples: silver, copper, gold, aluminum

DischargingIf a charged object has all of the excess electric charges removed, it is said to be discharged, or neutralized.

The simplest way to discharge any object is to bring it in contact with the Earth. This is called grounding.