Question

How do you measure self inductance?

Answer 1

Explanation:

1. Inductance is an electrical conductor's tendency to resist changes in the electric current passing through it.
2. An electromotive force is induced when the coil's current or magnetic flux changes. Self Inductance is the name given to this occurrence.
3. Inductance is usually measured in units called millihenrys or microhenrys. It is commonly measured by using a frequency generator and an oscilloscope or an LCM multimeter. It can also be calculated through a voltage-current slope measuring the change in the electrical current passing through the coil.
4. Oscilloscopes are intended for engineering work or troubleshooting systems that may contain complex signals that transmit at considerably higher rates than a digital multimeter can collect. Scopes have significantly faster measuring engines and much larger measurement bandwidths than digital multimeters, but they do not often have the same accuracy and resolution strength. Oscilloscopes typically have the resolution of a $3.5to4$-digit digital multimeter.

Draw a diagram,

Therefore, the self-inductance of the cylindrical coil is given by the formula:

$L=\frac{{\mu }_r{\mu }_0{N}^{2}A}{l}$

Where,

1. ${\mu }_r$ is the relative permeability of the material of the core
2. ${\mu }_0$ is the vacuum permeability
3. $N$ is the number of turns
4. $A$ is the area of cross-section
5. $l$ is the length of the coil

The self-inductance of a plane coil of N turns and mean radius r is

$L=\frac{{\mu }_0{N}^{2}r\pi }{2}$

Hence, this is the way to measure self-inductance.