134. Units of magnetic induction and magnetic flux

In the SI unit system, the law of electromagnetic induction is used to establish a magnetic flux unit.
This unit is called the Weber.

Since the EMF induction \(\Large{\varepsilon{_i}}\) is measured in volts, and the time in seconds, according to \((12-2)\) Weber can be defined as follows: the magnetic flux through the area limited by a closed loop is equal to one Weber, if the uniform decrease of this flux to zero in 1 second in the loop occurs EMF induction equal to 1 Volt. \(1 \,Wb \,= \,1 \,V \cdot 1 \,s\)

The unit of magnetic induction \(\overrightarrow{B}\) is set on the basis of the ratio \((12-1)\). If vector \(\overrightarrow{B}\) is perpendicular to the surface \(A\), then \(~ \Phi_B \,= \,BA\).

From here the magnetic induction is equal to one unit, if it creates through the area \(1\,m^2\) a magnetic flux of \(1 \,Wb\).

This unit of magnetic induction, as it was already told (see \(\S\)123), is called Tesla. \(1\,T \,= \,1 \,Wb/m^2\)