Recent content by lloyd21

I actually think I figured it out...3 percent error seems reasonable too, thanks a lot for everything though!

I did it three different times haha, all different ways, can you show me a picture of what it might look like?

I figured out the first part...I went and re did the lab again and got the max with completely different data. This second part though I am getting very off data and I think its because I'm not measuring right with the magnetic sensor...when measuring the magnetic inclination how should I hold...

I used the same link, that's how I found the somewhat "true" declination to be 1.54 degrees.

I just don't know what to do after that thread ended. If its wrong completely or if it was solved and that's why no one else responded haha. I've been stuck on that and another question for about a week and a half!

sorry the initial attempt was back emf = (5.6 x 10^-5)[+2.2 - (-2.2)/Δt] T = 1/f --> 1/2T = 1/f --> 2/f -- > T = 2/20000 = 1.0 x 10^-4 secs If this is the case then, by subbing, Δt = 1.0 x 10^-4 secs, into the above equation, I get: back emf = (5.6 x 10^-5)[+2.2 - (-2.2)/1.0 x 10^-4 secs] =...

So the first approach is much more accurate ? back emf = (5.6 x 10^-5)[+4.4 - (-4.4)/5.0 x 10^-5 secs] = (5.6 x 10^-5)[8.8/5.0 x 10^-5 secs] = (5.6 x 10^-5)(176000) = 9.856 V

This thread is the exact question I have, however I approached it differently, and this is what I got: n = 2(pie)fL = 2(pie)(20x10^3Hz)(5.6x10^-6H) = 7.04 (ohms) Then Irms = I/sqrt(2) = 2.2 A / sqrt(2) = 1.56 A Then Vrms = Irms x n = 1.56A x 7.04 (ohms) = 21.9V

any suggestions on what I can do to fix it, because it will affect my total field big time. This is the second part of it.

This was an answer added on later to this question in a different thread- - Okay, so if I am considering a whole period than my currents are actually +4.4 and - 4.4. Additionally, my period is actually just T = 1/f = 1/20000 = 5.0 x 10^-5. back emf = (5.6 x 10^-5)[+4.4 - (-4.4)/5.0 x 10^-5...

Homework Statement The coil in a loudspeaker has an inductance of L = 56uH (or 5.6 x 10^-5 H). To produce a sound frequency of 20 kHz, the current must oscillate between peak values of +2.2 A and -2.2 A in one half of a period. What average back emf is induced in the coil during this variation...

Was this answered correctly? 9.8 V?

I agree...it should be around 1.54 degrees...

yeah for sure, and made sure i started the calculation pointing towards true north. The data looks good I thought?