Chapter 16

Question 1

What is the Coulomb force?

What is the change in potential energy for it?

Answer 1

The electric force that is a conservative force
ΔPE=PEf-PEi=-Wcons
W=FxΔx
Or W=qEΔx=ΔKE
These all can be negative or positive

Comparison on slide 31-32 Nov 9

Question 2

What is the electric potential difference?

What’s its equation?

Answer 2

ΔV between points A and B
Change is potential energy asa charge moves from A to B, divided by the charge
Measured in volts (joule/coulomb)

ΔV=ΔPE/q

Question 3

What is the electron volt?

Answer 3

Kinetic energy an electron gains when accelerated through a potential difference of 1V
KEi+PEi=KEf+PEf
ΔKE=-ΔPE=-qΔV
ΔKE= -(-e)ΔV=e(1V)=1eV

Question 4

What is the difference between electric potential and potential energy?

Answer 4

Electric potential is characteristic of the field only, independent of a test charge that may be placed in field
Potential energy is a characteristic of the charge-field system due to an interaction between the field and a charge placed in the field

Look at example on slide 13 Nov 21

Question 5

How does electric potential work on a conductor?

Answer 5

Electric potential is constant everywhere inside a conductor and equal to that same value at the surface of the conductor
No work is required to move a charge from the interior of a charged conductor to its surface

Question 6

What are equipotential surfaces?

Answer 6

A surface on which all points are at the same potential
No work is required to move a charge at constant speed on this surface
Electric field at every point in perpendicular to the surface
Slides 17-18 nov 21

Question 7

What devices use ionization by high electric fields and forces between charges?

Answer 7

Electrostatic precipitator
Electrostatic air cleaner
Photocopier
Laser printer