Free Electrostatics MCQs with Answers
831 Electrostatics MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Electrostatics describes forces between charges through Coulomb's law, electric fields and field intensity, then uses electric potential to measure energy per unit charge. Capacitors store charge and electrical energy, with capacitance depending on geometry and dielectric material, not simply on the amount of charge present.
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Read the Electrostatics notesFree MDCAT chapter notes with key terms831 questions · page 31 of 42
- A. 9 µF
- B. 2 µF
- C. 10 µF
- D. 90 µF
- E. 5 µF
Explanation: 1/C1 + 1/C2 = 1/C⅓ + ⅙ = 1/C2 + 1 /6 = 1/C3/6 = 1/C½ =1 /CC = 2 µF
Correct answer: 2 µF- A. 9.6 x 10-¹⁹ J
- B. 12.1 x 10-¹⁹ J
- C. 14.5 x 10-¹⁹ J
- D. 16.7 x 10-¹⁹ J
- E. 18.5 x 10-¹⁹ J
Explanation: Given: Charge(q)=2e-Potential difference (V)= 3.0VFind:Energy=? Solution:Energy=Work…
Correct answer: 9.6 x 10-¹⁹ J- A. 60 μC
- B. 2.4 C
- C. 2.4 μC
- D. 60 C
Explanation: Use formula Q=CV, where C is .005 F and V is 12 V, and then convert the answer to μC by dividing it with 1000.0.005 x 12 / 1000 = 60 μC.
Correct answer: 60 μC- A. kg m s-3 A-1
- B. kg s-2 A-3
- C. kg2 m-2 s-3 A
- D. m s-1 A-3
Explanation: Force-mass x acceleration-kg x ms-2.Q=current(1) x time(t)=IT=A.sE=F/Q-kg ms-2/As .E=kgms-3A-1As it is a numerical, it can have only one…
Correct answer: kg m s-3 A-1- A. q2
- B. Only the positive charges
- C. All the charges
- D. +q1 and -q1
Explanation: At any point over the spherical Gaussian surface, the net electric field is the vector sum of electric fields due to +q1,-q and q2.Don't…
Correct answer: All the charges- A. The forces acting on them will be equal
- B. Their accelerations may be equal
- C. Magnitude of acceleration may be equal
- D. Magnitude of acceleration will be different
Explanation: Force on neutron = 0 (as charge = 0) Force on proton = qE Force on electron = - qE Masses of proton and electron are different.
Correct answer: Magnitude of acceleration will be different- A. W = 2Ep
- B. W = -2Ep
- C. W = Ep
- D. W = -Ep
Explanation: The potential energy of a dipole in an electric field is given by U = -pE cos θ.
Correct answer: W = 2Ep- A. Φ
- B. 0
- C. Φ/3
- D. Φ/6
Explanation: According to Gauss's Law, the total electric flux Φ through a closed surface is equal to the charge enclosed q divided by the permittivity…
Correct answer: Φ/6- A. A resultant force and torque
- B. Only force
- C. Only torque
- D. All of these options can be correct
Explanation: An electric dipole in a non-uniform electric field can experience various combinations of forces and torques.
Correct answer: All of these options can be correct- A. 0.25 m from the charge of 1 x 10^-9 Coulomb
- B. 0.75 m from the charge of 9 x 10^-9 Coulomb
- C. Both A and B
- D. At all points on the line joining the charges
Explanation: The position where the force on charge 𝑞 is zero is x=0.25 m from q1 and distance from q2 is 0.75m
Correct answer: Both A and B- A. Zero
- B. 4 N
- C. 4√2 N
- D. 8N
Explanation: When the first charge +Q is placed at a vertex, it exerts a force of 4 N on the central charge due to the Coulomb's law.
Correct answer: 4 N- A. Qr/x
- B. 2Qr/x
- C. 3Qr/x
- D. 6Qr/x
Explanation: When switch S is closed, the conducting sphere becomes influenced by both charges +Q and +2Q.
Correct answer: 3Qr/x- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: Initially, before the sphere is placed, the electric field lines run uniformly from the positively charged plate to the negatively charged…
Correct answer: Option C- A. A torque as well as a translational force
- B. A torque only
- C. A translational force only in the direction of the field
- D. A translational force only in the direction normal to the direction of the field
Explanation: The correct answer is that the dipole experiences both a torque and a translational force.
Correct answer: A torque as well as a translational force- A. -10 J
- B. -20 J
- C. -30 J
- D. -40 J
Explanation: The potential energy of a dipole in an electric field is given by the formula U = -pEcosθ, where p is the dipole moment, E is the electric…
Correct answer: -30 J- A. 2qE and minimum
- B. qE and pE
- C. Zero and minimum
- D. qE and maximum
Explanation: An electric dipole in a uniform electric field experiences no net force when its dipole moment is aligned with the field direction because…
Correct answer: Zero and minimum- A. 1/2 E2C(εr - 1)
- B. E2C
- C. E2C (εr − 1)
- D. None of these
Explanation: The mechanical work done in pulling the slab out of a disconnected capacitor involves calculating the change in stored energy.
Correct answer: 1/2 E2C(εr - 1)- A. k = 2
- B. k = 4
- C. k = 3
- D. k = 1
Explanation: To find the dielectric constant (k), we use the relationship between capacitance (C), charge (Q), and voltage (V): Q = C * V.
Correct answer: k = 3- A. Zero
- B. V= k (q/r)
- C. V=k qR2/r
- D. V=k qr/R2
Explanation: When a point charge q is placed at a distance r from the center of an uncharged conducting sphere of radius R (where R < r), the potential…
Correct answer: V= k (q/r)- A. The net force is zero
- B. The net force is directed along line BC
- C. The net force is directed normal to BC
- D. The net force is directed towards vertex C
Explanation: In an equilateral triangle, the symmetry of the charge arrangement results in forces that can be resolved into components.
Correct answer: The net force is directed normal to BC