Ap physics c ampere's law and biot-savart

AI Thread Summary
When deciding between Ampere's Law and the Biot-Savart Law for AP Physics C problems, consider the symmetry of the system. Ampere's Law is best applied in scenarios with high degrees of symmetry, such as solenoids, where it simplifies calculations. In contrast, Biot-Savart is more suited for cases lacking symmetry, requiring a more detailed approach. Typically, the problem will indicate whether symmetry exists, guiding the choice of method. Understanding these principles can streamline the problem-solving process in electromagnetism.
darksyesider
Messages
63
Reaction score
0
For AP Physics C level, I am having trouble on deciding whether to use Ampere's Law or use Biot-Savart.

Are there any hints/tricks for deciding what to use?
For example, in solenoids i heard it's easiest to use Ampere's Law
 
Physics news on Phys.org
If the system under consideration has high degrees of symmetry (e.g. spherical or cylindrical symmetry) then use Ampere's law. Biot-Savart is a brute force method that you only want to use when you have no symmetry arguments at your disposal. At the level of AP Physics C it will be obvious from the problem whether or not a system has high degrees of symmetry so as to allow for an elegant solution through Ampere's law.
 
This is from Griffiths' Electrodynamics, 3rd edition, page 352. I am trying to calculate the divergence of the Maxwell stress tensor. The tensor is given as ##T_{ij} =\epsilon_0 (E_iE_j-\frac 1 2 \delta_{ij} E^2)+\frac 1 {\mu_0}(B_iB_j-\frac 1 2 \delta_{ij} B^2)##. To make things easier, I just want to focus on the part with the electrical field, i.e. I want to find the divergence of ##E_{ij}=E_iE_j-\frac 1 2 \delta_{ij}E^2##. In matrix form, this tensor should look like this...
Thread 'Applying the Gauss (1835) formula for force between 2 parallel DC currents'
Please can anyone either:- (1) point me to a derivation of the perpendicular force (Fy) between two very long parallel wires carrying steady currents utilising the formula of Gauss for the force F along the line r between 2 charges? Or alternatively (2) point out where I have gone wrong in my method? I am having problems with calculating the direction and magnitude of the force as expected from modern (Biot-Savart-Maxwell-Lorentz) formula. Here is my method and results so far:- This...
Back
Top