Electric Potential Due to a Point Charge

Electric Potential Due to a Point Charge MDCAT MCQs with answers

7 past paper MCQs on Electric Potential Due to a Point Charge, from the Electrostatics unit of MDCAT Physics. The year each question appeared is shown where known; tap “Show answer” for the correct option and a short solution.

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1.The electric potential at a distance r is given by the formula: (NUMS MDCAT 2025)

  1. V = kq/r
  2. 1/4πε0qr
  3. Ed
  4. Ir
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Correct answer: (a) V = kq/r

The potential of a point charge at a distance $r$ is $kq/r$.

2.Two points charges, +5µC and -5µC are placed at points A and B, respectively, which are separated by a distance 2d. What is the electric potential at the midpoint M of the line joining A and B? (KMU MDCAT 2024)

  1. 2kQ/d
  2. kQ/d
  3. -kQ/d
  4. zero
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Correct answer: (d) zero

Potential is a scalar, and the two equal and opposite contributions cancel at the midpoint.

3.At midpoint P between two +4μc charges. V and E at midpoint P: (NUMS MDCAT 2024)

  1. V=0, E≠0
  2. V=0, E=0
  3. V≠0, E≠0
  4. V≠0, E=0
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Correct answer: (d) V≠0, E=0

The two potentials add and the two fields cancel, so the potential is finite and the field is zero.

4.Electric Potential which is measured with respect to the zero potential is called: (PMC MDCAT 2022)

  1. Absolute electric potential
  2. Change in K.E
  3. Change in potential energy
  4. Electric intensity
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Correct answer: (a) Absolute electric potential

Potential measured from infinity, where the potential is taken as zero, is the absolute potential.

5.If the potential at a point which is 1m from a charge is 1 volt, then the potential at a point which is 2m from the same charge will be: (PMC MDCAT 2020)

  1. 2 V
  2. 1 V
  3. 0.5 V
  4. 3 V
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Correct answer: (c) 0.5 V

The potential of a point charge goes as $1/r$, so twice the distance halves it.

6.Electric field strength of a point charge is E and electric potential is V, at a distance ‘r’ from the point charge. What is the electric potential at a point for the same point charge where electric field strength is E/4? (UHS MDCAT 2019)

  1. 4V
  2. 2V
  3. V/2
  4. V/4
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Correct answer: (c) V/2

$E$ goes as $1/r^2$ and $V$ as $1/r$, so a quarter of the field means twice the distance and half the potential.

7.Electric potential due to 2uC charge at distance of one meter is equal to: (UHS MDCAT 2018)

  1. 18 x 104volt
  2. 1.8 x 106volt
  3. 1.8 x 109volt
  4. 1.8 x 104volt
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Correct answer: (d) 1.8 x 104volt

$V=kq/r=9\times10^9\times2\times10^{-6}/1$, that is $1.8\times10^4\,\mathrm{V}$.

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