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Magnetic Flux - Practice Questions & MCQ

Edited By admin | Updated on Sep 18, 2023 18:34 AM | #JEE Main

Quick Facts

  • Magnetic flux is considered one of the most asked concept.

  • 39 Questions around this concept.

Solve by difficulty

Net magnetic flux through any closed surface is always zero $\vec{B} \cdot d \vec{s}=0$ is called

The induced emf in a coil is proportional to -

The number of magnetic lines of force passing normally through a surface is defined as

A coil is placed in magnetic field such that plane of coil is perpendicular to the direction of magnetic field. The magnetic flux through a coil can be changed:

A. By changing the magnitude of the magnetic field within the coil.

B. By changing the area of coil within the magnetic field.

C. By changing the angle between the direction of magnetic field and the plane of the coil.

D. By reversing the magnetic field direction abruptly without changing its magnitude.

Choose the most appropriate answer from the options given below :

The figure shows three regions of the magnetic field, each of area A, and in each region magnitude of the magnetic field decreases at a constant rate a. If  $\vec{E} $ is an induced electric field then the value of the line integral $\oint \vec{E} \cdot d \vec{r}$ Along the given loop is equal to:

A circular loop of radius r, carrying a current I lies in y-z plane with its centre at the origin. The net magnetic flux through the loop is : 

Which of the following is true about magnetic flux?

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Concepts Covered - 1

Magnetic flux

Magnetic flux-

The total number of magnetic lines of force passing normally through an area placed in a magnetic field is equal to
the magnetic flux linked with that area.

I.e for the below figure

Net magnetic flux through the surface is given by

$
\phi_B=\oint \vec{B} \cdot \overrightarrow{d A}=B A \cos \Theta
$

where
$\phi_B=$ Magnetic Flux
$B=$ Magnetic field
$\Theta=$ The angle between area vector and magnetic field vector

        

  • Magnetic flux is a scalar quantity.
  • Unit of magnetic flux -

It's S.I. unit is Weber (wb) or Tesla $\times m^2$ and its C.G.S. unit is maxwell(Mx). and $1 w b=1 \mathrm{Tm}^2$ and $1 M x=10^{-8} w b$

  • The dimension of magnetic flux is $M L^2 T^{-2} A^{-1}$
  • if $\theta=0$ then $\phi=B A$ and Flux will be positive.
  • If $\theta=\frac{\pi}{2}$ then Flux will be zero (i.e $\phi=0$ )

            

 

 

 

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Magnetic flux

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