Ampere''s law, Electrical Engineering

This is at the heart of the analysis of electromagnetics. It is based on a series of experiments conducted by the French scientist Ampere (1775 - 1836), in which the force between two long, parallel wires was measured and related to the current flowing in each.He found that the force per metre length of wire was related to the current in each wire, I1, I2 and the distance apart, r, by:

F ∝ I1.I2/r

From which he concluded that all magnetic fields are produced by the flow of electric current. Subsequent investigations have shown this to be the case - even for permanent magnets due tothe motion of electrons in the atomic structure of the material

Ampere went on to develop his famous 'Ampere's Law'

If the magnetic field is integrated along a closed path, the result is equal to the current enclosedAmpere's law can then be expressed mathematically as

293_ampere law.png

Where the dot product is used (= H.dl.cosθ) to indicatethat it is the magnetic field component resolved along the path direction at that point that is integrated. BothH and dl are vectors.

Although Ampere's Law applies to any closed path, it is convenient to choose a circular path, because the integration is then very easy.

394_ampere law2.png

Thus;293_ampere law.png

Becomes simply:1947_ampere law1.png

Note : If I is in amps and r in metres, then the units of H are Amps/metre

It is equally valid for an arbitrary path:

Arbitrary path enclosing a current carrying conductor. H(r) varies at different positions around the path

Direction of current is into the diagram. 

1961_ampere law3.png

The direction of the magnetic field produced by the current is given by the 'right hand corkscrew rule'

Note that Ampere's law applies to any closed path. If the path chosen does not enclose any current carrying conductors, then the result of the integration is zero.

Likewise, if more than one current carrying conductor is enclosed then the result of the integration will be the totalcurrent enclosed.

1243_ampere law4.png

Posted Date: 8/27/2012 3:51:34 AM | Location : United States

Related Discussions:- Ampere''s law, Assignment Help, Ask Question on Ampere''s law, Get Answer, Expert's Help, Ampere''s law Discussions

Write discussion on Ampere''s law
Your posts are moderated
Related Questions
weighted resistor and r2r ladder d/a converter

Q. Explain about Frequency Shift Keying? In this scheme frequency of the carrier signal is changed according to the data. Transmitter sends different frequencies for a "I" than

Dc basing bits: Operating point: operating is cut off; saturation and linear region of bits character are provided as follow: (1)  Linear-region operation (2)  (1)

Q. What do you mean by Digital Building Blocks? Whereas a continuous change from one value to another is the essential characteristic of an analog signal and continuous-state (

Q. In a depletion MOSFET for which V P = 3 V and I DSS = 11mA, the drain current is 3mA when v DS is set at the largest value that will maintain ohmic region operation. Find v G

Explain the Architecture of 8085. Ø  ALU Ø  Interrupt control Ø  Serial I/O control Ø  Timing and control unit Ø  Instruction Register & Decoding

Bad Workmanship Bad workmanship contributes importantly towards increasing distribution losses. Efforts should, thus, be made to have the best probable workmanship. In this co

Q. Show Noise and Stability of operational amplifier? Noise This refers to the small, rapidly varying, random spurious signals generated by all electronic circuits. Noise

CMA Complement Accumulator  Instruction Complement the  contents of the accumulator  i e the   accumulator  al once are converted zeros  and all zeros  are converted to  ones.

The conveyor system is driven by a 240 Volt 50 Hz AC motor requiring a continuous 1 Amp supply. The conveyor has single direction operation. The loading mechanism for the winder