A student connects three resistors in series to a power supply. The resistors have a power rating of % Watt. With the power supply set to 5V, she finds that the current is too small to measure with the DMM, so she turns the voltage up to 20V. After finishing her measurements, she turns the power supply off, builds a new circuit with the same 3 resistors in parallel, and turns the power supply on, still set at 20V. After a few seconds she smells burning, and finds that one of the resistors is very hot.
a) Sketch the two circuits the student built
b) Explain why the resistor overheated in the parallel circuit, but not in the series circuit.
c) What do you think the resistances of the three resistors were? Propose values that would be consistent with the scenario described above. Which resistor overheated the one with the smallest or largest resistance?
d) For the values of resistance you proposed in part c, calculate the current through each resistor, the voltage across each resistor, and the power dissipated by each resistor, for both the series and the parallel circuit.