Induction
Positive Rod

Positive Induction lesson illustration

What rule big rule of static electricity
explains why her hair is like this?

Positive Induction lesson illustration

www.bnl.gov

NOAA Photo Library

Enrichment

Positive Induction lesson illustration

Read About Faraday Cages in Wikipedia

A metal cage creates a shield against
very strong electric fields

University of Tehran High Voltage Lab. Person in cage: Prof. H.Mohseni

School blocks YouTube?
Use the file below.

Faraday_Cage.mov

Faraday Cage Protects from 100,000 V

Physikshow of the University of Bonn

Here's how it works

Positive Induction lesson illustration

Stanisław Skowron

Conduction
Fill in the Blank Notes

3. Induction - Positive Rod

[ Flash ]

No charge is transferred

Electrons redistributed

Induction with a Positive Rod

Positive Induction lesson illustration

Frame 1 - Neutral Electroscope

[ Flash ]

#p = #e-

Frame 2 - Rod comes near

[ Flash ]

Charge on electroscope?

#p = #e-

Electroscope is neutral

Charge of Knob (top)?

Negative

[ Flash ]

Charge of Leaves?

Positive

Frame 3 - Rod Removed,
Charges Return

[ Flash ]

Electroscope is neutral

"What would happen
to the leaves of this electroscope if a
positively charged rod
were brought near the
top of the electroscope?"

Positive Induction lesson illustration

"Electrons would be
attracted up from leaves toward positive rod.
Leaves would become
more positive and
diverge more."

"Which graphic shows

the electron distribution

of a neutral electroscope

near a positive rod?"

Positive Induction lesson illustration

Choice 4

Positive Induction lesson illustration

"Electrons are attracted up towards the positive rod"

Enrichment

Positive Induction lesson illustration

Like a Bird on a Wire

Electricity, Height and Women

Clip from Straight Up:
Helicopters in Action from David Douglas on Vimeo.

Segment from the helicopter documentary "Straight Up!", showing power line
maintenance being performed on live wires by a man outside a helicopter, using a type of Faraday cage.

Like_a_Bird_on_a_Wire.mov

Check Your Understanding

5 quick questions — pick an answer to see if you’re right.

1. A positive rod is held near the knob of a neutral electroscope. What is the knob's charge?

2. In the same situation, what is the charge of the leaves, and what do they do?

3. When the positive rod is removed without ever touching, the electroscope is

4. A positive rod is brought near the top of an electroscope that is already positive. What happens to the leaves?

5. A person inside a metal Faraday cage is unharmed by a huge spark outside. What does the cage do?

Negative Induction →