Chapter 9

Question 1

What is potential difference?

Answer 1

Measure of transfer of energy by charge carriers

Question 2

Equation for potential difference

Answer 2

V=W/Q

Question 3

What is the Electromotive force?

Answer 3

Describes when work is done as charge carriers. Same equation as potential difference

Question 4

What is an electron gun?

Answer 4

An electric device which shoots a beam of electrons

Question 5

How does an electron gun work?

Answer 5

Small metal filament is heated by an electric current and electrons in the wire gain kinetic energy. Some have enough to escape the surface of the metal. If the heated filament is placed in the vacuum and a high p.d applied between the anode and the filament (cathode). If the anode has a small hole, electrons can pass through creating a beam.

Question 6

Energy transfer of electron equation

Answer 6

eV=0.5mv^2

Question 7

Equation for resistance

Answer 7

Pd/current

Question 8

What is Ohm’s law?

Answer 8

V=IR

Question 9

Resistance and cross-sectional area equation

Answer 9

R (inversely proportional) 1/A

Question 10

Resistance from resistivity equation

Answer 10

R=pL/A

Question 11

Equation for power

Answer 11

P=VI