what are the conditions for applying ampere circuital law?

Grade 11

3 Answers

Ampere's circuital law in magnetism is analogous to gauss's law in electrostatics
This law is also used to calculate the magnetic field due to any given current distribution
This law states that
" The line integral of resultant magnetic field along a closed plane curve is equal to μ₀ time the total current crossing the area bounded by the closed curve provided the electric field inside the loop remains constant" Thus:
(Integeral Integeration) B.dl = uI

Last Activity: 9 Years ago

Some points get remained:

The integeral integeation above equation means that scalar product B.dl is to be integrated around the closed loop known as Amperian loop whose beginning and end point are same
Anticlockwise direction of integration as chosen in figure 9 is an arbitrary one we can also use clockwise direction of integration for our calculation depending on our convenience
To apply the ampere's law we divide the loop into infinitesimal segments dl and for each segment, we then calculate the scalar product of B and dl
B in general varies from point to point so we must use B at each location of dl
Amperion Loop is usually an imaginary loop or curve ,which is constructed to permit the application of ampere's law to a specific situation.

Last Activity: 9 Years ago

Follow the steps given to apply Ampere’s circuital law:

Step 1: Consider a symmetrical closed path such that it encloses direct current I once. This is Amperian path.

Step 2: Consider differential length dL depending on co-ordinate system used.

Step 3: Identify the symmetry and find in which direction H exists accoridng to co-ordinate system used.

Step 4: Find H*dL, the dot product. dL and H should be in same direction.

Step 5: Find integral of H*dL.around the closed path assumed. Equate it to current I enclosed by the path.

Soving this for H, we get required magnetic field intensity due to direct currnet I.

To apply Ampere’s circuital law, following conditions must be satisfied:

1. The H is either tangential or normal to the path, at each point of the closed path.

The magnitude of H must be same at all points of the path wher H is tangential. Thus, identifying symmetry and identifying components of H present, plays an important role while applying Ampere’s circuital law.

Last Activity: 9 Years ago