B) Resistance (__________) – Symbol  - _________

1)    R = _________ (equation)

   
V - _______________ (voltage) between ends of conductor

 

    I - _________________ (amperes)

 

 

 

 

 

 

2)    The resistance in a wire depends on:

      

 

a)    Resistivity - R -  - metals _____________________________ to electron flow

 

 

b)    ___________________ (_________) of the wire

 

 

 

c)     ___________________________) of the wire

 

         

 

Resistance of a wire = RL (meters) / A (m2)

 

 

 

3) Resistance and Temperature

 

 Metals – When temperature ______________, resistance _________

 

 

·        Nonmetals – When temperature _______________________,, resistance ________________

 

               

·        Superconductor - conductor with ________________________

 

Resistance in a wire                                                         

 

1) What is the resistance of .30 m length of copper wire that has a cross-sectional area of 5.0 x 10-5 m2?

 

 

 

 

a) How could you alter the dimensions of this wire to reduce the resistance?              

 

 

        To reduce the resistance in a wire you could __________________

 

 

 

2) If the length of a wire were halved, how would that change the wires resistance?

 

 

 

 

3) Which material on your reference table would produce a wire that would allow current to flow the best?