19 past paper MCQs on Electric Field and Field Intensity, 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.
1.A charged particle is moving in a uniform electric field. For the motion of the particle due to the field, which quantity has a constant non-zero value? (MDCAT 2022)
Correct answer: (a) acceleration
A uniform field gives a constant force, so the acceleration $qE/m$ is constant.
2.The electric field intensity inside a charged hollow sphere is: (MDCAT 2023)
Correct answer: (b) zero
The charge resides on the outer surface and its contributions cancel everywhere inside, so the field there is zero.
3.Which one of the following is NOT a feature of electric forces? (MDCAT 2024)
Correct answer: (b) they act on masses
Electric forces act on charge; it is the gravitational force that acts on mass.
4.The electric field at a point due to two equal and opposite charges is 100 N/C. If the magnitude of each charge is doubled then the electric field at that point becomes: (UHS MDCAT 2025)
Correct answer: (c) 200 N/C
The field of each charge is proportional to that charge, so doubling both doubles the resultant.
5.For two equal positive charges, the electric field weakest? (UHS MDCAT 2025)
Correct answer: (a) Midway between them
Midway between two equal positive charges the two fields are equal and opposite, so they cancel.
6.The electric field at a point is defined as: (KMU MDCAT 2025)
Correct answer: (d) Force per unit positive test charge
Field intensity is the force per unit positive charge placed at the point.
7.The point where the electric field is zero between two opposite charge lies: (SIBA MDCAT 2025)
Correct answer: (d) Nowhere between them
Between unlike charges both fields point the same way, so they add and never cancel.
8.A point lies 3m from a +5µC charge and 4m from a -3µC charge. The most appropriate direction of the net electric field at this point is directed: (SIBA MDCAT 2025)
Correct answer: (a) Away from +5µC charge
The nearer and larger charge gives much the stronger field, so the resultant points away from it.
9.The electric field at a point due to a point charge is 200N/C. If suppose a -4C test charge is placed at that point then the magnitude of electric field and electric force on it is: (SIBA MDCAT 2025)
Correct answer: (c) 200N/C and 800N
The field is a property of the source, so it stays $200\,\mathrm{N\,C^{-1}}$, and $F=qE=4\times200$ is $800\,\mathrm{N}$.
10.If a test charge of magnitude 2C experience forces of 100N and 200N at two points A and B in an electric field respectively. The ratio of electric fields at A to that of B is: (SZABMU MDCAT 2025)
Correct answer: (b) 1:2
The field is $F/q$ with the same $q$, so the ratio of fields is the ratio of forces, $1:2$.
11.A charged particle moves in a uniform electric field between two oppositely charged parallel metal plates. To calculate the force acting on the particle due to the electric field, which quantity is not required? (UHS MDCAT 2023)
Correct answer: (b) Particle speed
The field is the potential difference over the separation, and the force is $qE$; the speed does not enter.
12.When a charge gets influenced by its surrounding, it has entered: (PMC MDCAT 2022)
Correct answer: (a) An electric field
The region round a charge in which another charge feels a force is the electric field.
13.The force per unit charge is called: (PMC MDCAT 2022)
Correct answer: (d) Electric Intensity
Force per unit charge is the electric field intensity.
14.Which of the following could not be the units of electric intensity? (PMC MDCAT 2022)
Correct answer: (b) Joule per coulomb
Joules per coulomb is the volt, that is potential, not field.
15.Direction of electric force and electric field intensity for a positive charge is: (PMC MDCAT 2022)
Correct answer: (a) Parallel to each other
The field is defined as the force on unit positive charge, so for a positive charge the two are along each other.
16.Electric field intensity is: (NUMS MDCAT 2022)
Correct answer: (c) Force per unit charge
Field intensity is the force on unit positive charge.
17.Formula for electric field intensity is: (PMC Practice 2021)
Correct answer: (a) E=F/q
Field intensity is the force per unit charge.
18.The values of electric intensity will ____ due to the presence of dielectric medium: (PMC MDCAT 2020)
Correct answer: (c) Decrease
The medium divides the field by its relative permittivity.
19.Force experienced per unit positive test charge at a point in an electric field is the definition of: (UHS MDCAT 2018)
Correct answer: (b) Electric field strength
Force per unit positive test charge is the electric field strength.