Question

State whether true or false:
Relative permeability and absolute permeability have the same units.
A. True
B. False

Answer 1

In electromagnetism, permeability is the indicator of a material's ability to sustain the creation within itself of a magnetic field. Hence in reaction to an applied magnetic field, it is the degree of magnetization that a substance obtains. Typically, magnetic permeability is defined by the Greek letter $\mu$ .

Complete answer:
Relative permeability:
The ratio of the permeability of a specific medium to the permeability of free space is the relative permeability ${\mu _r}$, sometimes denoted by the symbol $r$. Since, it is a ratio, so it does have many units.

Absolute permeability:
The ratio between the magnitudes of the magnetic flux density $\overrightarrow B$ and the magnetic field intensity in the medium $\overrightarrow H$. Here,
$\mu = \dfrac{B}{H}$
It is measured in $Wb\,{\left( {Amps\,m} \right)^{ - 1}}$.

Hence, we can see that the units are not the same.option B is correct.

Additional information:
Diamagnetic substances get repulsion from a magnet. For e.g. – Copper, zinc
Paramagnetic substances get weakly attracted by a magnet with an externally initiated magnetic field. For e.g. - Magnesium, lithium.Ferro magnetic substances are strongly attracted by a magnet with an externally initiated magnetic field. For e.g. – iron, nickel.
There are many quantities related to diamagnetic, paramagnetic and ferromagnetic substances. The magnetic susceptibility is represented by $\chi$. Magnetic susceptibility is the measurement of how much a material is susceptible to magnetism. Relative magnetic permeability is represented by ${\mu _r}$.The relative magnetic permeability is the ratio of free space and vacuum. Magnetic permeability of a substance is represented by $\mu$
Magnetic permeability is the ratio between magnetic flux density $B$ and magnetic field strength $H$. Magnetic permeability in case of vacuum is given by ${\mu _ \circ }$.Magnetic permeability is a measurement of the resistance experienced when a magnetic field is created in a classical vacuum.

Note: Here we have to remember properly what relative permeability and absolute permeability is to know about the units. The expression Absolute Permeability of a substance is the product of free space permeability and Relative Permeability. A pure numerical number is the Relative Permeability and therefore has no units.