1.- According to the diagram, what is the resistance that when applying a voltage of 72. 10-8 volts would produce a current of 6. 10-7 amps?

2.- If the focus of the circuit in the diagram has a resistance of 10.0.10-8 and a current of 0.80 amps. What will be the voltage produced by the source?

3.- An aluminum conductor has a length of 801.0.10-6m and a diameter of 2.6m, calculate:

a) The area.

b) The resistance.

c) The current that circulates when the wire is connected to a difference of power of 20 volts, knowing that the coefficient of resistivity of aluminum is 2.8.10-8. m.

4.- There is a carbon conductor with a diameter of 2.40dm and a length 1,200.10-6km, calculate:

a) The resistance.

b) The current flowing when the wire is connected to a difference of potential of 60.10-3volts, knowing that the coefficient of resistivity of carbon is 3.5.10-6. m.