15 past paper MCQs on Magnetic Flux, from the Electromagnetism unit of MDCAT Physics. The year each question appeared is shown where known; tap “Show answer” for the correct option and a short solution.
1.Which surface has the greater magnetic flux in the same magnetic field, each having an area of $1\ \mathrm{m^2}$? (MDCAT 2022)
Correct answer: (d) the flux is independent of the shape
$\Phi=BA\cos\theta$ depends on the area and its orientation, not on the shape of the boundary.
2.The formula $\Phi=\vec{B}\cdot\vec{A}$ represents: (MDCAT 2024)
Correct answer: (b) magnetic flux
Magnetic flux is the scalar product of the magnetic field and the area it threads.
3.The SI unit of magnetic flux is: (NUMS MDCAT 2025)
Correct answer: (b) Weber
Magnetic flux is measured in webers, one weber being a tesla square metre.
4.The magnetic flux through a loop of 1m^2 in a 0.5T magnetic field is same as magnetic flux through a loop of 0.5 m^2 in a magnetic field of: (SIBA MDCAT 2025)
Correct answer: (a) 1.0 T at 0°
Flux is $BA\cos\theta$, so $0.5\,\mathrm{m^2}$ facing a $1.0\,\mathrm{T}$ field square on gives the same $0.5\,\mathrm{Wb}$.
5.157.The formula Φ = B.A represents (UHS MDCAT 2024)
Correct answer: (b) Magnetic flux
Flux density times area, taken as a scalar product, is the magnetic flux.
6.Q.161 Which surface has greater magnetic flux in same magnetic field, each has an area 1 m^2. (UHS MDCAT 2023)
Correct answer: (d) Flux is independent of shape
Flux is the product of flux density and area, whatever the outline of that area.
7.The weber is unit of measure of: (NUMS MDCAT 2023)
Correct answer: (c) Magnetic flux
Magnetic flux is measured in webers.
8.If 0.5 T field is applied over an area of 2-meter square which lies at an angle of 60 degree with the field, then the resulting flux will be: (UHS MDCAT 2023)
Correct answer: (b) 0.5 Wb
$\Phi=BA\cos\theta=0.5\times2\times\cos60^{\circ}$, which is $0.5\,\mathrm{Wb}$.
9.The magnetic flux is a _______ quantity: (PMC MDCAT 2022)
Correct answer: (a) Scalar
Flux is the scalar product of flux density and area, so it is a scalar.
10.Magnetic flux is defined as: (PMC MDCAT 2022)
Correct answer: (b) Magnetic field lines passing through a surface
Flux is the number of field lines crossing a surface.
11.The magnetic flux density is: (PMC MDCAT 2022)
Correct answer: (a) magnetic field lines per unit area
Flux density is the flux crossing unit area held at right angles to the field.
12.Q.68 Magnetic flux is maximum when Angle between magnetic field and vector area is: (NUMS MDCAT 2022)
Correct answer: (a) 0°
$\Phi=BA\cos\theta$ is greatest when the area vector lies along the field.
13.Magnetic flux is maximum when the angle, between the area vector and the magnetic field lines, is? (PMC Practice 2021)
Correct answer: (a) 0°
$\Phi=BA\cos\theta$ is greatest when the area vector lies along the field.
14.If the magnetic field is parallel to a surface, then the magnetic flux through the surface is: (PMC Practice 2021)
Correct answer: (a) Zero
With the field along the surface no lines cross it, so the flux is zero.
15.Magnetic flux is maximum when angle between magnetic field and vector area is: (PMC MDCAT 2020)
Correct answer: (a) 0
$\Phi=BA\cos\theta$ is greatest when the area vector lies along the field.