Charging by Induction PowerPoint Presentation, PPT - DocSlides

Charging by Induction

Charging by Induction: Temporarily

induced charge separationcharging by induction

When a charged object is brought close to, but not touching, a neutral object, the electrons in the neutral object move either away from or toward the charged object.

When electrons move within an object because of a nearby charged object, it is called

induced charge separation

.

Charging by Induction: Temporarily

Once the charged object is moved away, the electrons in the neutral object return to their original positions.

Charging by Induction: Temporarily

Animation of Temporary Induction

Charging by Induction: Temporarily

You can permanently charge an object using induction. To do this, you need to ground the neutral object.

Charging by Induction: Permanently

Charging by Induction: Permanently

A negatively charged object is placed near a neutral object, causing the electrons to move.

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Charging by Induction: Permanently

The neutral object is grounded, allowing the repelled electrons in the neutral object to escape to the ground. The neutral object loses electrons.

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_

Charging by Induction: Permanently

The ground is removed, leaving the ball with a positive charge.

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If electrons move from the neutral object through the wire to the ground (object loses electrons), the object becomes positively charged.If electrons move from the ground through the wire toward the object (object gains electrons), the object becomes negatively charged.

Charging by Induction: Permanently

Animation of Permanent Induction

Charging by Induction: Permanently

Applications of Static Electricity

Application

Science principles involved

How the application works

Electrostatic speakers

charging by induction, law of electric charges

In an electrostatic speaker, an audio transformer induces opposite electrical charges on two outer plates (stators) and then (b) reverses them.

Note: Charging by Induction

This method of charging objects involves

no contact between a charged object and a neutral object

, and

grounding

is used.

Note: Charging by Induction

1.

Negative

Neutral

Note:

Charging by Induction

1.

Negative

Neutral

e

-

Note: Charging by Induction

1.A negatively charged rod is placed near a neutral object. The excess electrons in the rod repel the _____________ in the object making them move as far away from the rod as possible. This shifting of electrons makes one side of the object __________________ and the other side _________________ (however, the object is still neutral). This is called _____________________________.

electrons

positive

negative

induced charge separation

Note:

Charging by Induction

2.

Negative

Ground

e

-

Note: Charging by Induction

2. If the neutral object is grounded, the repelled electrons move from the ____________ to the ___________ (the object _________ electrons).

object

ground

loses

Note:

Charging by Induction

3.

Negative

Positive

Note: Charging by Induction

3. When the ground is removed, the object is left with a _____________ charge (because it _________ electrons to the ground).

positive

lost

*** When objects are permanently charged by induction, the induced charge is always ______________ that of the charged object.

Note: Charging by Induction

opposite

Charging by Induction Questions1. Temporary Induction

A. A neutral metal-leaf electroscope.B. A negatively charged object is placed near (not touching) the metal ball of a neutral metal-leaf electroscope.C. The charged object has been removed.

Charging by Induction Questions1. Temporary Induction

A. A neutral metal-leaf electroscope.B. A negatively charged object is placed near (not touching) the metal ball of a neutral metal-leaf electroscope.C. The charged object has been removed.

e

-

Charging by Induction Questions1. Temporary Induction

A. A neutral metal-leaf electroscope.B. A negatively charged object is placed near (not touching) the metal ball of a neutral metal-leaf electroscope.C. The charged object has been removed.

e

-

Charging by Induction Questions1. Temporary Induction

A. A neutral metal-leaf electroscope.B. A negatively charged object is placed near (not touching) the metal ball of a neutral metal-leaf electroscope.C. The charged object has been removed.

e

-

Charging by Induction Questions2. Permanent Induction

A. A positively charged object is placed near (not touching) a neutral

electroscope

.B. The electroscope is then grounded. C. The ground is removed. Then the charged object is removed.

Charging by Induction Questions2. Permanent Induction

A. A positively charged object is placed near (not touching) a neutral

electroscope

.B. The electroscope is then grounded. C. The ground is removed. Then the charged object is removed.

e

-

e

-

p. 489 # 2, 3, 4, 6

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