Module 04 โ Circuits and Current ยท quiz worth 30 pts
Series and parallel look similar in a schematic until you trace from one battery terminal around and back.
One path or more than one path. That is the first decision.
Start at the positive terminal. If you never have a choice of wire, it is series.
Two resistors that both start at the same point and both end at the same point are parallel.
I = V/R on each element. Series: same I, add the voltages. Parallel: same V, add the currents. Do not collapse the table into one equivalent-resistance formula.
The Canvas worksheet uses PhET Circuit Construction Kit: DC. Build the series table, then the parallel table, with at least three different bulb resistances.
Comparing Series and Parallel Circuits โ Watch if path-count is still fuzzy. Then do the three-resistor numbers on paper before opening the sim.
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Current needs a voltage source and an unbroken path. The path is usually wire. Devices on that path use the current and add resistance. How those resistances are arranged changes the overall resistance, and therefore the current. The two simple layouts are series and parallel. Many building circuits mix both; that mix is a series/parallel circuit.
In series, resistors sit one after another on a single path. Charge has only that path. If it opens, current stops everywhere. Holiday lights wired in series go all dark when one bulb burns out. Adding resistors in series increases total resistance and decreases the flow rate of charge. Compass deflection around a simple series loop is the same at different points: there is one current on that one path.
Holiday lights are the memory hook.
Total resistance goes up. Compass deflection in the course activity gets smaller.
The only path is gone. Everything goes dark.
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In parallel, two or more resistances connect between the same two points. Charge can take any complete branch. If one bulb burns out, the other complete branches can stay lit. With the same components and the same voltage, more electrons flow through the parallel arrangement than through the series arrangement, so total current is higher. Adding resistors in parallel decreases total resistance and increases the flow rate of charge.
Extra branches share the same two points.
Total resistance goes down. Total current goes up at the same battery voltage.
Other complete branches can still carry current.
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The lesson's comparison uses the same source voltage and the same parts, rearranged.
One path is series. Shared endpoints for two or more resistors is parallel.
I = V/R. If the layout raises total R, current falls. If it lowers total R, current rises. That is why the parallel compass deflection is larger in the course activity.
The 04.05 Circuit Construction Kit work is a data table, not a multiple-choice quiz. In series, the current through each bulb is the same. Compute each V = IR, check that those voltages add to the source, then P = IV for each bulb. In parallel, the voltage across each bulb is the same. Compute each I = V/R, check that those currents add to the source current, then P = IV for each bulb. Do not replace that table with a single equivalent-resistance formula. This lesson never writes one.
Find each bulb voltage, check the source voltage, and find each power.
V = 2.0 V, 4.0 V, 8.0 V. Source 14.0 V. P = 2.0 W, 4.0 W, 8.0 W. One open resistor stops this whole loop.
Find each branch current, check the source current, and find each power.
I = 4.0 A, 2.0 A, 1.0 A. Source 7.0 A. P = 32 W, 16 W, 8.0 W. One open branch leaves the other complete branches working.
Fill the table. Do not hunt for one replacement resistor.
Same I through each. V = IR per bulb. Add those V values. P = IV per bulb.
Same V across each. I = V/R per branch. Add those I values. P = IV per bulb.
Got it now? Scroll back up and re-read the section โ it should land differently.
Adding series resistors lowers flow rate. The holiday-light failure mode is total blackout, not extra current.
Parallel means shared endpoints and extra paths. Extra series bulbs on the same line are still series.
A building circuit can be series/parallel. Name the part that is one-path and the part that branches.
For each item, count complete paths before choosing.
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