assignment 28

course phys202

1.Explain how to obtain the magnetic field due to a given current through a small current segment, and how the position of a point with respect to the segment affects the result.- the equation uses is, B = k ' I L / r^2 * sin(theta) and IL is the source

2.How much charge flows from each terminal of 7.00 microF capacitor when connected to 12.0 volt battery?

-when connected to the battery the charge stored is C=Q/V, so the stored energy is Q=C *V. 7.00 * 12= 7.00C/volt* 12 volts= 83 C

3. Explain how to obtain the magnetic field due to a circular loop at the center of the loop. For current running in a circular loop:

- We can use the radius of the loop and can split up the loop into increments which would be dL and the source being I dL. (I `dL / r^2), after getting each increment one can add then all up and have a magnitude of B = sum(k ' I `dL / r^2). R and I are constants so the equation can be changed to B = k ' I / r^2 sum(`dL).

3. magnetic fields produced by electric currents.What evidence do we have that electric currents produce magnetic fields?

- magnetism can be explained by them, when to currents are next to each other magnetic fields are formed and nearby metal objects may attract

4.What would be the area of a .20 F capacitor if plates are separated by 2.2 mm of air?

- The equation used is E = 4 pi k sigma = 4 pi k Q / A, which you can do for each plate. Then the voltage between the plates are V = E * d, d=seperation. Then the capacitance is C = Q / V = Q / (4 pi k Q / A * d) = A / (4 pi k d) which we need to solve for C, C = A / (4 pi k d) for A for the area we get A = 4 pi k d * C, then plug in C=.20F and they are separated by 2.2mm

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