Magnetic induction

Magnetic induction refers to a physical quantity that describes the strength and direction of a magnetic field. It is a vector, commonly represented by the symbol B, and the international unit is Tesla (symbol T). Magnetic induction is also known as magnetic flux density or magnetic flux density. In physics, the strength of the magnetic field is represented by the magnetic induction intensity. The greater the magnetic induction intensity, the stronger the magnetic induction. The smaller the magnetic induction intensity, the weaker the magnetic induction.

There is a magnetic field around the current (moving charge), and its important external performance is: it has the effect of magnetic field force on the moving test charge, current-carrying conductor or permanent magnet introduced into the field, so the effect of the magnetic field on the moving test charge can be used to describe the magnetic field , and thus introduce the magnetic induction intensity B as the basic physical quantity to quantitatively describe the characteristics of each point in the magnetic field, and its status is equivalent to the electric field intensity E in the electric field. 

The reason why this physical quantity is called magnetic induction intensity, but not magnetic field intensity, is because the term magnetic field intensity has been used to represent another physical quantity in history. The difference: magnetic induction intensity reflects the interaction force, which is the two reference points A and B The stress relationship between the two, and the magnetic field strength is a unilateral quantity of the main body, regardless of whether the B side is involved or not, this quantity is unchanged.