Reluctance is obtained by dividing the length of the magnetic path l by the permeability times the cross-sectional area A; thus
r = l/μA
, the Greek letter mu, μ, symbolizing the… The reluctance of a magnetic circuit is analogous to the resistance of an electric circuit.
What is an example of reluctance?
Reluctance is hesitation or unwillingness to do something.
When you really don’t want to go out in the rain
, this is an example of reluctance.
How do you calculate mmf?
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.
What is the reluctance of the core?
The reluctance of a core
depends on the composition of the material and its physical dimension
and is similar in concept to electrical resistance. The relationship between mmf, flux, and magnetic reluctance is analogous to the relationship between emf, current, and resistance, as shown in Figure 1-26.
What is the reluctance in magnetic materials?
Magnetic reluctance, or magnetic resistance, is a concept used in the analysis of magnetic circuits. It is defined as
the ratio of magnetomotive force (mmf) to magnetic flux
. It represents the opposition to magnetic flux, and depends on the geometry and composition of an object.
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?
Hint :EMF
stands for electromotive force
. EMF is the force that is responsible for driving the electrons in an electric circuit. Magnetomotive force is abbreviated as MMF. MMF is the driving force required to drive the magnetic flux through the circuit.
How do you use reluctance?
- With some reluctance , mostly from Martha this time, we agreed. …
- He tossed in a hint of reluctance , just for good measure. …
- There was evidence of her reluctance to discuss some element of the accident.
What is high reluctance?
The lower the reluctance, the easier it is for magnetic flux to flow through the core material. Materials that are easily magnetised have a low reluctance and a high permeability, and
non-magnetic materials
have a high reluctance and a low permeability.
What is the base word of reluctance?
The word comes from the
Latin reluctari
, or to struggle against.
What is the reciprocal of reluctance?
Permeance
is the reciprocal of reluctance is a measure of magnetic flux for a number of current turns in a magnetic circuit. The SI unit of magnetic permeance is Weber per ampere-turn that is H (henry). … The permeance is analogous to the conductance in an electrical circuit.
What is the inductance unit?
Henry
, unit of either self-inductance or mutual inductance, abbreviated H, and named for the American physicist Joseph Henry. One henry is the value of self-inductance in a closed circuit or coil in which one volt is produced by a variation of the inducing current of one ampere per second.
What is reluctance path?
Definition:
The obstruction offered by a magnetic circuit to the magnetic flux
is known as reluctance. … Also in an electric circuit, the electric field provides the least resistance path to the electric current. Similarly, the magnetic field causes the least reluctance path for the magnetic flux. It is denoted by S.
What is magnetization formula?
Magnetization is a measure of the density of magnetism and may be calculated from the number of magnetic moments in a given volume. … This may be shown as
M = Nm/V
where M is the magnetization, N is the quantity of the magnetic moment, m is its direction and V is the volume of the sample.
What is the formula of permeability?
Permeability is the inductance per unit length. In SI units, permeability is measured in henries per metre
(H/m = J/(A
2
⋅m) = N/A
2
)
.
What is flux unit?
1. flux unit –
a measure of the strength of a magnetic field per unit area
. magnetic flux unit. magnetic flux – a measure of the strength of a magnetic field over a given area. maxwell, Mx – a cgs unit of magnetic flux equal to the flux perpendicular to an area of 1 square centimeter in a magnetic field of 1 gauss.
