19+Circuits

toc =Use www.physicsclassroom.com= to work this worksheet: http://www.physicsclassroom.com/getattachment/curriculum/circuits/circuit.pdf Test on this =Videos:= [] =Notes:= The goal of series-parallel resistor circuit analysis is to be able to determine all voltage drops, currents, and power dissipations in a circuit. The general strategy to accomplish this goal is as follows:
 * __ Analysis technique __**
 * Step 1: Assess which resistors in a circuit are connected together in simple series or simple parallel.
 * Step 2: Re-draw the circuit, replacing each of those series or parallel resistor combinations identified in step 1 with a single, equivalent-value resistor. If using a table to manage variables, make a new table column for each resistance equivalent.
 * Step 3: Repeat steps 1 and 2 until the entire circuit is reduced to one equivalent resistor.
 * Step 4: Calculate total current from total voltage and total resistance (I=V/R eq ).
 * Step 5: Taking total voltage and total current values, go back to last step in the circuit reduction process and insert those values where applicable.
 * Step 6: From known resistances and total voltage / total current values from step 5, use Ohm's Law to calculate unknown values (voltage or current) (V=IR or I=V/R).
 * Step 7: Repeat steps 5 and 6 until all values for voltage and current are known in the original circuit configuration. Essentially, you will proceedstep-by-step from the simplified version of the circuit back into its original, complex form, plugging invalues of voltage and current where appropriate until all values of voltage and current are known.
 * Step 8: Calculate power dissipations from known voltage, current, and/or resistance values.



Study carefully the examples that are found on page 742 and beyond. Use the information found in the table found on page 742 to evaluate the relationship of the voltages, currents and resistance in the different areas of the circuit.



Video:
Solving complex circuit media type="custom" key="22065148"

Lab 2
Do lab 1 media type="custom" key="11881750" media type="custom" key="11881782"

Discussion:
[|andreashaycumberland] Feb 8, 2010 8:31 am You use a lot of the same formulas you did in Current and Resistance, so you may have to go back and write those down. Be careful when deciding parallel and in series circuits; some can be kind of hard to tell. If there's more than one parallel couple in a series make sure to get the equivalent resistance of the individual parallels then add. The lab is pretty straight forward just make sure to make the circuit correctly.
 * re: 20Circuits**

[|nchshadenj] Feb 17, 2010 8:43 am This is a very simple section. Problems are worked with just a couple of formulas. You may have to refer back to some of the formulas in Chapter 19. Table 20-2 on page 742 is necessary to work problems dealing with parallels and series circuits. If you have problems asking you to find the equivalent resistance of a circuit in a figure and the figure is not there, they are listed in order on page 757 in your Physics book. -Haden J.

[|nchshadenj] Feb 26, 2010 9:56 am The labs are easy. You just use PhET to create model circuits. You test their resistance, voltage, and current and answer a few simple questions reviewing what you learned in the chapter. -Haden J.

[|nchsclarkm] Apr 30, 2010 7:10 am This unit is pretty much Current and Resistance's older and slightly more difficult brother. The most difficulty I had with it is determining which values I should use in my formulas. For one Voltage you may not use all of the resistors and for another one you might. It just depends on what you are finding, so pay close attention. Overall the packet wasn't difficult and the lab was a walk in the park. (set a resistor to 0 ohms when you make a circuit for a little entertainment.)