Step 1 : Understanding the Question:
The topic of this question is Magnetism and Electromagnetic Induction, specifically focusing on the measurement units of magnetic quantities. Magnetic flux is a measure of the total magnetic field that passes through a given area. It is conceptually similar to the "flow" of magnetic field lines through a surface. The question asks to identify the standard international (SI) unit used to quantify this flux.
Step 2 : Key Formulas and approach:
The approach involves looking at the mathematical definition of magnetic flux to see how its units are derived:
1. Formula: $\Phi_B = B \cdot A \cdot \cos \theta$
2. Unit Analysis: Flux Unit = (Unit of Magnetic Field) $\times$ (Unit of Area).
3. Derived Unit: $1 \text{ Flux Unit} = 1 \text{ Tesla} \cdot \text{m}^2$.
Step 3 : Detailed Explanation:
Magnetic Flux ($\Phi_B$) represents the product of the average magnetic field times the perpendicular area that it penetrates.
The SI unit for magnetic field ($B$) is the Tesla (T). The SI unit for area ($A$) is square meters ($m^2$).
Therefore, the unit for magnetic flux is Tesla-square meter ($T \cdot m^2$).
This derived unit is officially named the "Weber" (Wb) in the SI system, named after the German physicist Wilhelm Eduard Weber.
Let's check the other options to eliminate them: (A) Tesla is the unit for magnetic field intensity (B), not flux.
(C) Henry is the unit for Inductance (L), which relates to how flux changes with current.
(D) Coulomb is the unit for Electric Charge (Q).
Since the question specifically asks for magnetic flux, the Weber is the only correct choice. One Weber is defined as the amount of flux that, linking a circuit of one turn, produces in it an electromotive force of one volt if it is reduced to zero at a uniform rate in one second.
Step 4 : Final Answer:
The SI unit of magnetic flux is the Weber, which corresponds to option (B).