Question

SI unit of Magnetic flux is;
(a). Ampere-meter
(b). Ampere m2
(c). Weber
(d). Weber/m2

Answer 1

- Hint: Flux is always defined as the amount of particular quantity that passes through the specific area.

Complete step-by-step solution -

Magnetic flux is the number of magnetic field lines passing through the given closed surface. Magnetic flux can be found out by integrating the normal component of magnetic field (B) over the surface. It is commonly represented as \[\phi \text{ or }{{\phi }_{B}}\] .Weber (Wb) is the SI unit of magnetic flux.
\[{{\phi }_{B}}=B.A=BA\cos \theta \]
Where B is the magnetic field, A is the area and \[\theta \] is the angle at which magnetic field lines pass through the given surface area.
So, the correct answer is option (c).

ADDITIONAL INFORMATION:

The CGS unit of magnetic flux is Maxwell. Fluxmeter or magnetometer is used to measure the magnetic flux. When the angle between the B and A is nearly equal to \[90{}^\circ \], then the flux is very low. When the angle is equal to \[0{}^\circ \], the resulting flux is maximum.
If we are using non-uniform magnetic fields we have to add each area element and their corresponding magnetic field.
Magnetic flux is used to describe the magnetic force effect in a specific area. Even though weber is the SI unit of magnetic flux, commonly it expressed in several other forms such as
\[\dfrac{kg{{m}^{2}}}{{{s}^{2}}A}=\dfrac{J}{A}=V.s=Wb\]
Where, V is the volt, s is the second, J is the joule and A is the Ampere.

Note: Wb is the unit of magnetic flux while Wb/m2 is the unit of magnetic flux density. It is important to understand the difference between them. Tesla is also used to represent the Wb/m2. One Tesla (T) is equal to Weber per square meter.