Question

The SI unit of magnetic field induction is
a) Tesla
b) Weber
c) Weber/m
d) Weber-m

Answer 1

Hint: The magnetic field induction refers to the field intensity per unit area. The intensity of the field is usually given by the magnetic flux across a given area. The magnetic flux is given by, $\Phi =BA\operatorname{cos}\theta $, where B is the value of the magnetic field intensity across the area A and $\theta $ is the angle between the normal of the area and B. From this expression we will obtain the SI unit of B.

Complete step by step answer:
To begin with let us write the SI unit for area i.e. A and magnetic flux $\Phi $.
The SI unit magnetic flux is Weber (W)and that of the area is square meter (${{m}^{2}}$). Let us assume that there is 100 percent intensity of the magnetic field passing through the given area. Hence we can write the equation of flux as,
$\Phi =BA$ Hence the intensity of magnetic field is given by,
$B=\dfrac{\Phi }{A}W{{m}^{-2}}$. If we compare the options there does not exist the obtained unit for the field intensity. This unit obtained is not the Si unit of field intensity , but the SI unit of field intensity is Tesla (T).
Hence the correct answer is option a.

Note:
In the question it is assumed that 100 percent intensity of the magnetic field passes through the given area. But it is not necessary cause the unit will remain the same. The assumption is made so that we can write the magnetic field intensity in terms of flux through a given area.