resistance 2.2

Question 1

What is the potential difference?

Answer 1

The energy converted from electrical potential energy to another form of energy per coulomb of charge flowing from one point to another

Question 2

What is the emf?

Answer 2

The energy converted into electrical potential energy per coulomb of charge flowing through the source

Question 3

What is ohms law?

Answer 3

The current in a metal wire at constant temperature is proportional to the pd across it

Question 4

What obeys ohms law?

Answer 4

-wire
-fixed resistors

Question 5

What disobeys ohms law?

Answer 5

-Filament lamp
-Silicon diode

Question 6

Explain superconductivity

Answer 6

-Electrons pair up
-“cooper pairs” no longer interact with lattice
-No collisions=no energy transfer
-Lattice offers no resistance to current flow

Question 7

What is the critical temperature of mercury?

Answer 7

-it is where the resistance is 0
-4.2 K

Question 8

What are some of the uses of superconductors?

Answer 8

-Powerful electromagnets (due to high currents)
-Particle accelerators
-MRI machines
-Tokamaks