15: Static Electricity

Question 1

What are the two types of electric charges?

Answer 1

Positive and negative.

Question 2

What is the charge of protons, neutrons, and electrons respectively?

Answer 2

P: 1.60 x 10^-19 C
N: no charge
E: -1.60 x 10^-19 C

Charge is measured in coulombs (C)

Question 3

Explain why an atom is electrically neutral.

Answer 3

It has an equal number of protons (+) and electrons (-), which balances the charges out.

Question 4

Atoms become charged when…

Answer 4

…the number of protons and electrons are not equal. When electrons are removed, the atom becomes positive, and when electrons are added, the atoms become negative.

Question 5

Can protons be removed from or added to an atom?

Answer 5

No. Only electrons.

Question 6

Define electric field.

Answer 6

A region of space where an electric charge q experiences an electric force due to the presence of another electric charge.

Question 7

What are electric field lines?

Answer 7

Imaginary lines that are used to visualise the pattern of an electric field.

Question 8

Electric field lines move ______ from positive charges, and the opposite for negative charges.

Answer 8

outwards

Question 9

Describe the current I in a series circuit.

Answer 9

The current is the same at every point.
I(1) = I(2) = I(3)

Question 10

Describe the p.d. I in a parallel circuit.

Answer 10

The sum of the p.d. across each component is equal to the p.d. across the whole circuit.
V(ε) = V(1) + V(2)
ε = V(1) + V(2)

Question 11

What is the formula for calculating resistance?

Answer 11

R = V/I

Question 12

Describe the current I in a parallel circuit.

Answer 12

The c