Design a circuit using only 9 V batteries and resistors that will provide nodal
voltages of 4 V, 3 V, and 2 V. Write an appropriate input deck for SPICE to
simulate your solution, and submit a printout of the output file with the desired
voltages highlighted. Draw a labeled schematic on the printout for reference,
with node numbers identified.
A very long string of multicolored outdoor lights is installed on a house. After
applying power, the homeowner notices that two bulbs are burned out. (a) Are
the lights connected in series or parallel? (b) Write a SPICE input deck to
simulate the lights, assuming 20 AWG wire, 115 V ac power supply, and an
individual bulb rating of 1 W. There are 400 lights in the string; simulate an
electrically equivalent circuit with fewer than 25 components for simplicity.
Submit a printout of the output file, with the power supplied by the wall socket
highlighted. (c) After replacing the burned-out bulbs, the homeowner notices
that the lights closest to the outlet are approximately 10 percent brighter than
the lights at the far end of the string. Provide a possible explanation, keeping in
mind that nothing in the string is zero ohms.
