Electromagnetism

Electromagnetism MDCAT MCQs with answers

68 past paper MCQs from Physics unit 10, Electromagnetism, across 4 topics. They are arranged topic by topic; bigger topics show a sample here and link to their full set and to study notes. Tap “Show answer” for the correct option and a short solution.

Practise as a quiz

Magnetic Flux Density

1.The source of a magnetic field is: (MDCAT 2022)

  1. an isolated magnetic pole
  2. a static electric charge
  3. a current loop
  4. a stationary magnet only
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Correct answer: (c) a current loop

Moving charge is what makes a magnetic field, and the current loop is its simplest source.

2.Which of the following statements is incorrect for magnetic field lines? (MDCAT 2024)

  1. lines start at the north pole and end at the south pole
  2. lines never touch or cross each other
  3. the lines are curved
  4. the magnetic field is strongest where the lines are farthest apart
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Correct answer: (d) the magnetic field is strongest where the lines are farthest apart

The field is strongest where the lines are closest together, not farthest apart.

3.The unit of magnetic flux density is: (MDCAT 2024)

  1. $\mathrm{Wb\,m^{2}}$
  2. $\mathrm{Wb\,m}$
  3. $\mathrm{Wb\,m^{-2}}$
  4. $\mathrm{Wb}$
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Correct answer: (c) $\mathrm{Wb\,m^{-2}}$

Flux density is flux per unit area, and $1\ \mathrm{Wb\,m^{-2}}=1$ T.

All 23 Magnetic Flux Density MCQs → Magnetic Flux Density notes →

Magnetic Flux

4.Which surface has the greater magnetic flux in the same magnetic field, each having an area of $1\ \mathrm{m^2}$? (MDCAT 2022)

  1. circular
  2. rectangular
  3. square
  4. the flux is independent of the shape
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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.

5.The formula $\Phi=\vec{B}\cdot\vec{A}$ represents: (MDCAT 2024)

  1. electric flux
  2. magnetic flux
  3. electric flux density
  4. gravitational flux
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Correct answer: (b) magnetic flux

Magnetic flux is the scalar product of the magnetic field and the area it threads.

6.The SI unit of magnetic flux is: (NUMS MDCAT 2025)

  1. Tesla
  2. Weber
  3. Henry
  4. Farad
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Correct answer: (b) Weber

Magnetic flux is measured in webers, one weber being a tesla square metre.

All 15 Magnetic Flux MCQs → Magnetic Flux notes →

Force on a Charged Particle in a Magnetic Field

7.Electric forces change the magnitude and direction of velocity, while magnetic forces change the: (MDCAT 2022)

  1. magnitude only
  2. direction only
  3. magnitude and direction
  4. neither magnitude nor direction
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Correct answer: (b) direction only

The magnetic force is always perpendicular to the velocity, so it does no work and only turns the particle.

8.The magnitude of the magnetic force on a current-carrying conductor in a uniform magnetic field is maximum if the conductor is: (MDCAT 2023)

  1. perpendicular to the magnetic field
  2. parallel to the magnetic field
  3. at $45^\circ$ to the magnetic field
  4. antiparallel to the magnetic field
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Correct answer: (a) perpendicular to the magnetic field

$F=BIL\sin\theta$ is greatest when $\theta=90^\circ$.

9.A proton is projected with a uniform velocity \$v\$ along the axis of a current carrying solenoid. Then: (UHS MDCAT 2017)

  1. the proton will be accelerated along the axis
  2. the path of the proton will be circular about the axis
  3. the proton moves along a helical path
  4. the proton will continue to move with velocity $v$ along the axis
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Correct answer: (d) the proton will continue to move with velocity $v$ along the axis

Inside the solenoid the field is along the axis, so the velocity is parallel to it and $F=qvB\sin0^{\circ}=0$.

All 24 Force on a Charged Particle in a Magnetic Field MCQs → Force on a Charged Particle in a Magnetic Field notes →

Path of a Charged Particle in a Magnetic Field

10.The path of a charged particle in a plane perpendicular to a uniform magnetic field is: (NUMS MDCAT 2025)

  1. Circular
  2. Helical
  3. Parabola
  4. Elliptical
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Correct answer: (a) Circular

With the velocity always at right angles to the field, the magnetic force is centripetal and the path is a circle.

11.If mass of a charged particle is doubled, cyclotron frequency becomes: (NUMS MDCAT 2025)

  1. Doubled
  2. Halved
  3. Quadrupled
  4. One fourth
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Correct answer: (b) Halved

The cyclotron frequency is $qB/2\pi m$, so twice the mass halves it.

12.When a charged particle enters the magnetic field parallel then it will: (SZABMU MDCAT 2023)

  1. Deflect toward north
  2. Deflect toward south
  3. Move straight
  4. Move in circular path
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Correct answer: (c) Move straight

With the velocity along the field the sine is zero, so there is no force and the path stays straight.

All 6 Path of a Charged Particle in a Magnetic Field MCQs → Path of a Charged Particle in a Magnetic Field notes →

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