Consider the two circuits depicted in Figure 20.81. In circuit 1, ohmic resistor R1 dissipates 5 watts; in circuit 2, ohmic
resistor R2 dissipates 20 watts. The wires and batteries have negligible resistance. The circuits contain 10-volt batteries.
(a) What is the resistance of R1 and of R2?
(b) Resistor R1 is made of a very thin metal wire that is 3 mm long, with a diameter of 0.1 mm. What is the electric
field inside this metal resistor?
(c) The same resistors are used to construct circuit 3 (Figure 20.82), using the same 10-volt battery as before. Make a
complete accurate graph of potential versus location for circuit 3. Label the y axis numerically. Be sure to explain
the significant features of your graph.
(d) On a copy of the diagram of circuit 3, place +'s and −'s to indicate the distribution of surface charge everywhere on
the circuit. (No explanation is needed for this part d.)
(e) In circuit 3, calculate the number of electrons entering R1 every second and the number of electrons entering R2
every second.
(f) What is the power output of the battery in circuit 3?