Magnetic permeability and the definition of the amp, Electrical Engineering

The ampere has been defined (by the International Committee of Weights and Measures in 1946) as the current flowing in two long parallel wires 1 metre apart that produces a force of 2 x 10-7 Newtonsper metre length between the wires.

1884_magnetic permeability.png

So with the same current flowing in both wires spaced 1 metre apart, it is easy to increase the current until a force of 2 x 10-7 Newtons is measured between them. We then know that the current flowing is exactly 1 amp (by definition). This definition also gives the value of k = 2 x 10-7  Newtons.metre/amp

If we express one of the currents in terms of the magnetic field that it produces, then we obtain an equation for the force per metre lengthexperienced by a current carrying conductor in a magnetic field. This is by far the most useful form of the equation in practice:

897_magnetic permeability1.png

Since   k = 2 x 10-7  then we write the new constant as  µwhere

µ0 =  4π x 10-7 Henrys/metre  

(note the Henry is a unit of measure of inductance

µ0 is known as the magnetic permeability of free space

Posted Date: 8/27/2012 4:17:42 AM | Location : United States

Related Discussions:- Magnetic permeability and the definition of the amp, Assignment Help, Ask Question on Magnetic permeability and the definition of the amp, Get Answer, Expert's Help, Magnetic permeability and the definition of the amp Discussions

Write discussion on Magnetic permeability and the definition of the amp
Your posts are moderated
Related Questions
3-Phase 3 Wire Meter A 3-phase 3 wire meter has 2 elements of each category on the other hand of 3 elements as in the case of 3-phase 4 wire meter. The primary principle of op

AC Motors DC motors that have their magnetic fields produced by coils as described earlier can, in principle,  be powered from AC as well, since if the applied voltage reverse

I am working on Vision based vehicle lane keeping control system. I have uploaded two images at & at

Q. For an RG-290/U aluminum rectangular wave - guide, a = 58.42 cm and b = 29.21 cm. Compute the theoretical and practical frequency ranges of operation for the guide.

how to use tabular method to solve convolution problems

Three Phase Induction Motors A three  phase induction rotor  consists  a stators  and a motor stator has balanced three  phase  winding. These windings  are distributed in the

Equivalent Circuit of a DC Machine A review of the material presented with regard to elementary direct-current machines can be helpful at this stage to recall the principles of

Q. Describe binary number system? The binary number system has a base of 2 with two distinct digits (bits), 1 and 0. A binary number is expressed as a string of 0s and 1s, and

Q. D flip-flop - latch or delay element? The symbol for the clocked D flip-flop is shown in Figure (a), in which the two output terminals Q and ¯ Q behave just as in the SRFF,