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course Phy 242
April 30 around 7:30pm.
Physics II 1104111. Set up circuit 1 and measure the quantities you need to determine the rate at which potential energy changes across each bulb.
Report your results and how they were obtained from your data:
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I had an abnormal circuit on this one. When I hooked up the volt meter across one bulb, I got V = 0.017 and A=-0.0013, but when I hooked it up across the other one, I got V = 1.58 and A = -0.069. CRAZY!
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2. Repeat with circuit 2.
Report your results and how they were obtained from your data:
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I hooked the volt meter across the top bulb and the amp meter with the generator and the middle bulb and got V = 2.72 and A = -0.1943.
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3. Set up circuit 3 and measure the quantities you need to determine the rate at which potential energy changes across the bulb and across the capacitor. Do these rates change with time?
As time changes the bulb in circuit 3 dims, and current and voltage change. Have the probe interface create graphs of the changing quantities, from which you can determine the changing rate at which potential energy changes across each circuit element.
From some of your graphs you can also determine how the resistance of the bulb changes with current. Do so.
Report your results and how they were obtained from your data:
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When I hooked the volt meter across the bulb, I got V = 1.332 to 0.019 and A = 0.0584 to 0.0043. However, when I hooked the volt meter across the capacitor, I got V = 0.129 to 2.199 in 60 seconds and A = 0.0648 to 0.0034. Very interesting circuit.
@& You should also some detail about the shape of these graphs.
How would the V vs. t and A vs. t graphs give you a graph of resistance vs. current?
How would your graphs give you a graph of power vs. time?*@
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4. Circuit 4 is identical to circuit 3, except that you should use a resistor instead of a bulb. Repeat the preceding with this circuit. Does the resistance change with current?
Report your results and how they were obtained from your data:
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I didn’t get to do this one for some reason. I must’ve accidently skipped it. My guess would be that yes, the resistance WOULD change with current.
@& Had you obtained results for current vs. voltage, how would this help you determine resistance vs. current?*@
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5. Set up circuit 5, using a coil of magnet wire and a steel bolt for its core, and see if you can detect the (very short) time it takes the current through the coil to build.
Report your results and how they were obtained from your data:
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I set the volt meter across the coil and the amp meter in line with the generator and coil and got V = 0.017 and A = -0.1318
@& This won't help to find the time required for the circuit to build.*@
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6. Set up circuit 6, using a piece of nichrome wire as the variable resistor. You can vary the resistance by sliding the contact point back and forth along the wire. Obtain a graph of current vs. time as you vary the resistance up and down.
Report your results and how they were obtained from your data:
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I set the volt meter across the nichrome wire and amp meter in the same position. I slid a piece of wire across the nichrome wire for 10 seconds. After looking at the graphs, here’s 3 data points for each graph:
CURRENT graph: (0,-0.6250), (5,-0.3808), (10,-0.1443) concave down
VOLTAGE graph: (0,-2.042), (5,-2.313), (10,-2.588) concave up
I liked this circuit, very cool.
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7. Set up circuit 7 and again vary the resistance of the nichrome wire up and down. Observe capacitor voltage vs. current. Are the two in phase?
Report your results and how they were obtained from your data:
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I hooked the volt meter across the nichrome wire and amp meter still the same. I observed capacitor voltage vs the current. Voltage goes from -2.5 to -0.007 and current goes from 0.0456 to 0.0012.
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8. Don't yet set up circuit 8. You won't be able to vary the resistance quickly enough to get an effect from the coil. However, based on your observations for circuit 5, how quickly do you think you would need to vary the current in order that the time required for the current to build in the coil might have a significant effect?
Report your results and how they were obtained from your data:
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9. Set up circuit 9, using the double-pole-double-throw switch. Throw the switch at regular intervals, as quickly as possible while maintaining a regular rhythm. Slowly increase the resistance from minimum to maximum and observe the change in the relative phases of the current and capacitor voltage.
Report your results and how they were obtained from your data:
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10. Set up circuit 10 using two magnet wire coils and see if you can detect a brief current through the ammeter with each throw of the switch. If so, determine whether the current is in phase or out of phase, and to what extent, with the current through the first coil.
If you can detect a current, then see if you can detect a voltage.
Report your results and how they were obtained from your data:
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&#Good responses. See my notes and let me know if you have questions. &#