Electrostatic electricity

Question 1

What is electricity?

Answer 1

• All phenomena caused by positive and negative electrons

- A form of energy

Question 2

Electricity is most widely used by what?

Answer 2

• Machines of all kinds

- You (your brain)

Question 3

When is an object positively charged?

Answer 3

When an object has more protons than electrons

Question 4

What is electrostatic electricity?

Answer 4

The movement of electron charges and keeping balance

Question 5

Can protons and electrons move?

Answer 5

only electrons

Question 6

What charges can be transferred between two materials? What charges remain in place?

Answer 6

• negative (electrons)

- positive (protons)

Question 7

Do charged objects ever return to their natural state?

Answer 7

Charged objects recover their natural state very quickly and will be evenly charged

Question 8

Opposite charges do what?

Answer 8

Attract

Question 9

Same charges do what?

Answer 9

Repel

Question 10

What are conductors?

Answer 10

A material or object that allows for free flow of electrical charge

Question 11

What are insulators?

Answer 11

A material or object that impedes the free flow of electrical charge

Question 12

What can negative charges do?

Answer 12

• leave or enter an object creating a net charge on the object
• move within an object that is a conductor disturbing charge within the object

Question 13

How does an object get positively charged?

Answer 13

Objects lose negative charges/lose electrons

Question 14

How does an object get negatively charged?

Answer 14

Objects gain negative charges/gain electrons

Question 15

What are the 3 ways objects can be charged?

Answer 15

• Friction (rubbing)
• Conduction (contact)
• Induction (approaching/close)

Question 16

Describe the friction of two neutral objects

Answer 16

• Two neutral objects rub against each other
• Friction pulls electrons away from one of the objects transferring them to the other (depending on electron affinity)
• One is positively charged and one is negatively charged (one gained, one lost electrons)

Question 17

Describe conduction

Answer 17

• Touching of a charged object to a neutral one
• When they touch (and are removed) the charge of one object will be shared between both objects
• They will both have the same charge after

Question 18

Describe induction

Answer 18

• A charged object getting close to a neutral one
• Get close to exert a power of attraction
• The charged object will cause movement of charges according to the low of charges
• If its +, then + move back and - are at the front

Question 19

What creates a dipole?

Answer 19

Uneven distribution of charges

Question 20

What happens when a charges object is brought into contact with the neutral dipole? What is this called?

Answer 20

Conduction

The neutral object will get the same charge as the object that is charged

Question 21

What happens when a charged object is brought close to the neutral dipole? What is this called?

Answer 21

Induction

The two objects would attract

Question 22

What happens if a charged object is brought REALLY close to the neutral dipole?

Answer 22

A spark COULD occur between the two objects (electrical discharge) which neutralizes the charge from or to the surroundings

Question 23

What could make a spark occur? What does this cause?

Answer 23

If a charged object is brought REALLY close to the neutral dipole

This neutralizes the charge from or to the surroundings

Question 24

What happens if two neutral objects are rubbed together? What is this called?

Answer 24

Friction

If two neutral objects are rubbed together, the negative charges may get transferred from one material to the other

Question 25

How is the direction of the negative charges determined?

Answer 25

It is determined by how strong each material is attracting them (electron affinity)

Question 26

What does a high electron affinity mean?

Answer 26

They have a greater pull on electrons

Question 27

You rub polyester on rubber and rub nylon on gas.

What happens when polyester is then brought in contact with nylon?

Tribo:
polyester, rubber, cotton, fur, nylon, glass

Answer 27

The polyester and nylon will repel eachother

Question 28

Explain the comb/water thing

Answer 28

check notes but INDUCTION

Question 29

What is the Coulomb law?

Answer 29

The force between 2 charged objects at rest depends on:

• distance between the objects
• amount of charge on each object

Question 30

Describe the effect of distance on force between two charged objects

Answer 30

As distance increases, force decreases

Question 31

Describe the effect of charge on force between two charged objects

Answer 31

As the amount of charge increases, force increases

Question 32

In Coulomb’s law, what does Fe mean?

Answer 32

Force between the objects (in Newtons (N))

Question 33

In Coulomb’s law, what does q1 & q2 mean?

Answer 33

amount of charge on the objects (1&2) (in Coulomb (C))

Question 34

In Coulomb’s law, what does r mean?

Answer 34

Distance between the objects (in metres (m))

Question 35

What is the charge carried by one electron/proton?

Answer 35

6.25x10^-18 C

Question 36

What is the unit of measurement for an electrical charge?

Answer 36

Coulomb (C)

Question 37

What is the k in the force equation calculation?

Answer 37

the constant

(9x10^9) Nm2/C2

Question 38

Two objects have charges of 5x10^-8 and 2x10^-8. They are 10cm apart.

What is the force between them?

Answer 38

Fe= 9x10^-4 N

Question 39

Practice Force/Coulomb calculation

Answer 39

check notes