Class 12 Physics Electromagnetic Induction | Magnetic Flux |

**Magnetic Flux**

- Magnetic flux is defined as the product of the average magnetic field times the perpendicular area it penetrates.
- In case of magnetic flux orientation of the area vector is considered.
- Area vector is considered as the amount of lines crossing an area also varies with the orientation of the area.
- It is a scalar quantity.
- Magnetic flux is denoted by Φ
_{B}or Φ. - I Unit- Weber (Wb).
- Where 1Wb= 1Tesla x 1m
^{2}(S.I. unit of B = Tesla and Area=m^{2})

- Where 1Wb= 1Tesla x 1m
- G.S unit-Maxwell (Mx).Relationship between Weber and Maxwell is;1Wb=10
^{8}Mx - Mathematically:
- Φ
_{B}=**A****B**=magnetic field vector,**A**= area vector- Area vector =In case of magnetic flux the amount of lines crossing an area varies with the orientation of the area.

- Φ
_{B}= BA cos θ- Where θ=angle between magnetic field and area vector.

- Φ
- Direction of area vector is determined by the normal to the area vector.

Case 1: When the angle between the area vector and the magnetic field (θ)= 90^{0}.

- Therefore, Φ
_{B}= 0 as cos90^{0}=0.

Case 2: When the angle between the area vector and the magnetic field (θ)= 0^{0}.

- Therefore,Φ
_{B}= BA as cos 0=1.

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