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course PHY 232
5/2 11:00 am I left out the integrals and comp part and also didn't get some of the circuits built since we sidetracked into the coil/current lag setup using different cores and I did include those results
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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V measured across bulb and graphed vs time
Bulb 1(rt hand bulb) --> 1.43V/30s constant and I =0.065 --> `d PE = V*I = 1.43*0.065 = 0.093 J/s
Bulb 2 --> 1.68 V --> 0.065 A --> `d PE = 1.68*0.065 = 0.10 J/s
#$&*2. Repeat with circuit 2.
Report your results and how they were obtained from your data:
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V measured across each bulb & ammeter in series in the loop that contains the bulb V is measure across.
Bulb 1 --> V = 2.97 V--> I= 0.098 --> `d PE = 0.29 J/s
Bulb 2 --> V = 2.93 --> I = 0.187 --> `d PE = 0.55 J/s
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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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Quantities do change with time.
I measured V & I wrt t and the ammeter was in series w/ circuit and first V across Bulb was measured.
V, I, t
2.84, 0.1, 2.2
1.8, 0.078, 11.2
0.89, 0.05, 23.5
0.07, 0.01, 47.3
Across cap
V, I, t
0.186, 0.1, 1.5
1.3, 0.07, 11.8
2.2, 0.052, 23.2
3, 0.01, 47
V across Bulb falls off and V across cap increases but both time I decreases. So `d PE across bulb goes to 0 and so does across cap but is never as high as bulb and cap moves up to a peak and then down but bulb just goes down.
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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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Here we only had time to measure V & I across cap but not R.
V, I, t
0.11, 0.09, 5.5
1.5, 0.045, 23.2
2.4, 0.02, 47
This time it seems cap just falls off from init value. R= V/I and here R starts off small but increases greatly by t =47.
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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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ammeter in series and voltmeter not used
Tried very hard without core and finally found t= 0.198 --> I = 0.003 then t=0.199 --> I = 0.62 so definite leap but not is one big jump rather than building up.
With core t= 0.267--> I=0 then t=0.268 --> I = 0.62 so same as before we didn't have enough resolution to determine the lag.
Tried smaller coil on top of very large coil with t=0.049 I= 0 then t=0.05 --> I = 0.595 then t= 0.051 --> I = 0.62 so we had a buildup interval but not enough to really measure the time lag.
Tried very large coil and had
t, I
0.030, 0
0.031, 0.47
0.032, 0.616
0.033, 0.62
So this is the best result we got and it's over a minuscule interval and shows definite lag.
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!!!!!!
This is as far as we got with the circuits and the rest is computational
!!!!!!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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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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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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University Physics:
11. Find the electric field at (0, 0, z) due to charge Q uniformly distributed over the disk x^2 + y^2 < a^2 in the x-y plane. You CAIN'T do this too good using the flux model. Set up an integral based on Coulomb's Law.
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12. Find the magnetic field at (0, 0, z) due to current I running counterclockwise around the circle x^2 + y^2 = a^2 in the x-y plane.
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13. Find the line integral of the magnetic field due to an infinite line current I, around a circle centered at and in a plane perpendicular to the wire. You can let the radius of the circle be a.
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14. Find the energy necessary to bring charges q_1 and q_2 to proximity r, given that they are originally separated by a great distance.
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15. Find the energy necessary to bring a capacitor with capacitance C from an uncharged state to charge Q.
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16. Find the energy necessary to assemble, from distance charges, a uniform spherical charge distribution of radius a, containing charge Q.
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@& This looks good.
Make sure you can do those integrals. Shouldn't give you much trouble, but let me know if they do.*@