Resistance

The resistance of ohmic conductors dosen't change with the current. The current flowing across an ohmic conductor is directley proportional to the potentional diffrence across the conductor (at a constant temprature). 

Sometimes the resistance does change across the components. 

For a diode the resistance depends on the direction of the current. They will happily let the current flow in one direction, but have a massive resistance if it is reversed. 

The formula for potentional diffrence is:

Potentional diffrence (v)=Current(A) x Resistance 

This can be written as V=IR

Resistance can be changed by whether the circuit is in Series or Parallel. The length of the wire can be another affect of the resistance. 

Required practical:

1) Attach a crocodile…