Magnetomotive force (mmf),
F
m
= NI ampere-turns (At)
, where N = number of conductors (or turns) and I = current in amperes. Since ‘turns’ has no units, the SI unit of mmf is the ampere, but to avoid any possible confusion ‘ampere-turns’, (A t) are used in this chapter. … Hence, mmf = NI = Hl At.
What is magnetomotive force what is its unit?
The unit of magnetomotive force is
the ampere-turn
, represented by a steady, direct electric current of one ampere flowing in a single-turn loop of electrically conducting material in a vacuum. Magnetomotive force is the force that sets up a magnetic field within and around an object.
What is MMF define by formula?
Magnetomotive force (MMF) is
a component or part of the equation of magnetic flux in magnetic circuits
. As an analogy to electromotive force, MMF “drives” magnetic flux through a magnetic circuit. Magnetomotive force is also known as magnetic potential.
What is the magnetizing force?
The force exerted by a magnet which is determined by the sum of all lines of magnetic flux present in a magnetic field
.
What is the symbol for magnetomotive force?
magnetomotive force (m.m.f.) (symbol:
F
m
; unit: ampere; ampere-turn)
What is flux density formula?
Flux density is simply
the total flux divided by the cross sectional area of the part through which it flows – B = Φ / A
e
teslas
. Thus 1 weber per square metre = 1 tesla. Flux density is related to field strength via the permeability. B = μ × H.
What is mmf and EMF?
EMF stands for electromotive force
.
MMF stands for magnetomotive force
. It is defined as the driving force responsible for the movement of the electrons in an electrical circuit. It is defined as the driving force responsible for the creation of magnetic flux in a magnetic circuit.
What is the use of magnetomotive force?
magnetic circuits
The magnetomotive force, mmf, is analogous to the electromotive force and may be considered the factor that sets up the flux. The mmf is equivalent to
a number of turns of wire carrying an electric current
and has units of ampere-turns.
What is self inductance?
Self-inductance is
the tendency of a coil to resist changes in current in itself
. Whenever current changes through a coil, they induce an EMF, which is proportional to the rate of change of current through the coil.
What is the unit of Permeance?
The units of permeance are
Weber per ampere-turns (Wb/AT) or Henry
.
What is difference between H and B?
The difference between B and H is that
B is used for representing the magnetic flux density
while H is used for representing the magnetic field intensity.
What is coercive force?
:
the opposing magnetic intensity that must be applied to a magnetized material to remove the residual magnetism
.
What is absolute permeability?
Absolute Permeability is
the ability of a reservoir rock to allow fluids to flow through its pores
. It indicates the flow capacity of formation. It is simply referred to as permeability. Absolute Permeability is used to analyze the formation rock.
What is BQv?
F=BQv. The
magnetic force
acting on a charged particle travelling through a magnetic field at right angles to the field is given by F=BQv, where B = magnetic flux density, Q = charge, v= speed of particle. The derivation for this equation is as follows: Imagine the path of the charged particle as a wire.
Which metal can be magnetized?
Iron is magnetic
, so any metal with iron in it will be attracted to a magnet. Steel contains iron, so a steel paperclip will be attracted to a magnet too. Most other metals, for example aluminium, copper and gold, are NOT magnetic. Two metals that aren’t magnetic are gold and silver.
What is U in magnetic field?
Magnetic permeability μ (Greek mu) is thus defined as
μ = B/H
. Magnetic flux density B is a measure of the actual magnetic field within a material considered as a concentration of magnetic field lines, or flux, per unit cross-sectional area.
