You have a 6-volt battery (assumed ideal) and a 1.5-volt flashlight bulb, which is known to draw 0.5A when the bulb voltage is 1.5V (see figure below). Design a network of resistors to go between the battery and the bulb to give vs=1.5V when the bulb is connected, yet ensures that vs does not rise above 2V when the bulb is disconnected.

There are two schematic diagrams below. Please enter the network of resistors you’ve designed into both diagrams. The top diagram is the model when the bulb is connected; the bottom diagram is the model when the bulb is disconnected.

Run a DC analysis on both diagrams to show that the node labeled “A” has a voltage of approximately 1.5/V/ in the top diagram and less than 2/V/ in the bottom diagram. Please submit your results /after/ the DC analyses have been run so that the results of the analyses will also be submitted. Because we will be checking the voltage at node A, you should have an assigned voltage at node A after the DC analysis; otherwise, your submission will be deemed incorrect.

Schematic model when bulb is connected:

Schematic model when bulb is disconnected

/Hint/: use a two-resistor voltage divider to create the voltage for node A. You’ll have two unknowns (R1 and R2) which can be determined by solving the two equations for /vs/ derived from the constraints above: one involving R1, R2 and R bulb where /vs/=1.5, and one involving R1 and R2 where /vs/=2.

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