Thanks.
This will be posted along with others at access site
24-72-057
Real ammeter: assembled by putting a magnet in the bottom of a cup, dangling a strip of aluminum with a piece of a straw threaded on it just over the magnet, with the two ends of the aluminum attached to the rest of the circuit
Electronic ammeter: store bought, uses a battery, etc
Trial #1
Complete circuite with the nichrome:
25% deflection of the real ammeter w/o the electronic ammeter
17% deflection of the real ammeter with the electronic ammeter -> it read 40 mA
Trial #2
Complete circuit w/o the nichrome:
40% deflection of the real ammeter w/o the electronic ammeter
20% deflection of the real ammeter with the electronic ammeter -> it read 70 mA
Trial#3
Complete circuit with a nichrome channel branching off
40% deflection of the real ammeter w/o the electronic ammeter
25% deflection of the real ammeter with the electronic ammeter -> it read 85 mA
From the results of the experiment, it's very clear that the electronic ammeter used some of the mA that was flowing through the circuit which made the real ammeter deflect less than should be expected.
The nichrome proves to be a great resistor compared to the rest of the circuit."
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In this lab we took an amp meter, a volt meter, two AA batteries and a 50 cm NiCh wire. We then made a series with the batteries first then the amp meter then the volt meter then the NiCh wire then back to the battery. Our volt meter was reading 2.4 volts but the batteries added up to 3 volts so there was resistance in the NiCh. The surface area of the NiCh is 1x10^-3 m^2. Then we ran the wire through a pvc cylinder so then we wanted to find the flux of the wire on the cylinder so to find the flux we did the following, flux= (4*pi*(charge density of wire*length of wire))/( 2*pi*(radius of tube*length of tube).
While all this information was very helpful to learn, the really helpful analysis was over the units of the flux. Instead of just stating Flux = 4'pi*k*Q, we substituted the calculation for Q in to see what was happening and see that 4pi*K*(charge density * length) gives us the flux. This is expanded upon by dividing this Flux by the surface area of the ""imaginary"" cylinder, which in turn gives us the charge density of the cylinder. Surface area was simply calculated by multiplying 2pi*radius*length. " ""
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We measured the milliamps (mA) with the nichrome attached to the circuit, without the nichrome attached to the circuit, and with the nichrome attached but circled back around itself to cancel itself out. # of mA with nichrome=105mA
# of mA without nichrome=205mA
# of mA with nichrome circled back around itself=195mA
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we didn't take exact measurements for everything that the class before us did. But this is the overview of what we did.
Overview of class March 26th 2012
Today in class, we hooked up two AA batteries in order from our positive volt meter to our homemade am meter, then through NiCl, then to the negative side of the volt meter.
We observed before hand the difference in resistance the NiCl gives us compared to not having it hooked up in our system. In our Volt meter, we set the resistance to 10 volts,
and read out around 1.4 volts. Also in class, we learned how to calculate flux and what it means through a cylinder, and how the current flows off the
surface area of that cylinder using the law of symmetry. "
A real ammeter attached to a 1.5 volt battery on each side by wire leads. The deflection will be considered as 100%.Trial 1:
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1.5 volt battery attached to wire lead, then to the ""real"" ammeter, another wire lead, to a 42cm piece of NiCh (NiChrome), to another wire lead which is attached to the other side of the battery.
Deflection with the NiCh is approx. 50%
Trail 2:
A 1.5 volt battery attached to wire lead, to ""real"" ammeter, wire lead, 42cm NiCh, wire lead, electronic ammeter, wire lead, to opposite end of battery.
Deflection is still 50%. No change by adding the electronic ammeter. Electronic ammeter reading = 100-105 mA
Trail 3:
A 1.5 volt battery attached to a lead, then to a ""real"" ammeter and a 42 cm piece of NiCh, to an electronic ammeter (also attached to the other end of the 42 cm NiCh), to the opposite end of the battery.
Deflection is 70% (bypassing the NiCh). Electronic ammeter reading = 195 mA
Trial 4:
1.5 battery attached to ""real"" ammeter by wire lead, ""real"" ammeter attached to electronic ammeter by wire lead, then to opposite side of battery.
Deflection is 70% (no NiCh). Electronic meter reading = 205mA
"
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1.)System with clamp wire coming from battery source then attached to “real” amp meter. Clamp wire coming from “real” amp meter then attached to nick wire. Clamp wire coming from nick wire then attached to “fake” amp meter. Clamp wire coming from “fake” amp meter and then attaching to the battery source.Fake amp meter read 40 mA
Real amp meter moved 1/6 or about 17% of a magnet length
The fake amp meter was then removed from the system.The clamp wire was reattached to the battery source.
Real amp meter moved ¼ or about 25% of a magnet length
17%/25%=.68
The fake amp meter changed to real amp meter by 32%
2.) System with clamp wire coming from battery source then attached to “real” amp meter. Clamp wire coming from “real” amp meter then attached to nick wire. Clamp wire coming clamp attached to nick wire(allowing nick wire to hang loose, unattached to anything at other end) then attached to “fake” amp meter. Clamp wire coming from “fake” amp meter and then attaching to the battery source.
Fake amp meter read 70mA
Real amp meter moved 1/5 or about 20% of a magnet length
The fake amp meter was then removed from the system. The clamp wire was reattached to the battery source.
Real amp meter moved 2/5 or about 40% of a magnet length
20%/40%= .5
The fake amp meter changed the real amp meter by 50%
3.) System with clamp wire coming from battery source then attached to “real” amp meter. Clamp wire coming from “real” amp meter then attached to nick wire. Clamp wire coming from nick wire then attached to “fake” amp meter. Clamp wire coming from “fake” amp meter and then attaching to the battery source. Clamp wire is added between the two clamp wired that are attached to the ends of the nick, providing a bypass.
The fake amp meter read 85mA
The real amp meter moved ¼ or about 25% of a magnet length
The fake amp meter was then removed from the system. The clamp wire was reattached to the battery source.
Real amp meter moved 2/5 or about 40% of a magnet length
25%/40%= .625
The fake amp meter changed the real amp meter by 37.5%
This shows that the presence of the nick does cause some loss of energy from the system. This loss is obviously smaller than the gain of energy received by adding more paths for the energy to flow through.
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