Electrostatics Practice Test — Class 12 Physics

12th Standard Physics — Electrostatics: Online Practice Test

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Two identical point charges of magnitude –q are fixed as shown in the figure below. A third charge +q is placed midway between the two charges at the point P. Suppose this charge +q is displaced a small distance from the point P in the directions indicated by the arrows, in which direction(s) will +q be stable with respect to the displacement?

இரு -q மின்துகள்களுக்கு இடையில் உள்ள +q மின்துகள் மற்றும் அதன் இடப்பெயர்ச்சி திசைகள் A1, A2, B1, B2 காட்டப்பட்டுள்ளன.

A.A1 and A2 B.B1 and B2 C.both directions D.No stable

Which charge configuration produces a uniform electric field?

A.point charge B.uniformly charged infinite line C.uniformly charged infinite plane D.uniformly charged spherical shell

What is the ratio of the charges \(q_1 / q_2\) for the following electric field line pattern?

இரண்டு மின்துகள்களைச் சுற்றியுள்ள மின்புலக் கோடுகளின் வரைபடம்.

A.\(1/5\) B.\(25/11\) C.\(5\) D.\(11/25\)

An electric dipole is placed at an alignment angle of \(30^\circ\) with an electric field of \(2 \times 10^5 \text{ N C}^{-1}\). It experiences a torque equal to \(8 \text{ N m}\). The charge on the dipole if the dipole length is \(1 \text{ cm}\) is

A.\(4 \text{ mC}\) B.\(8 \text{ mC}\) C.\(5 \text{ mC}\) D.\(7 \text{ mC}\)

Four Gaussian surfaces are given below with charges inside each Gaussian surface. Rank the electric flux through each Gaussian surface in increasing order.

மின்துகள்களை உள்ளடக்கிய நான்கு காஸியன் பரப்புகள் A, B, C, D காட்டப்பட்டுள்ளன.

A.\(D < C < B < A\) B.\(A < B = C < D\) C.\(C < A = B < D\) D.\(D > C > B > A\)

The total electric flux for the following closed surface which is kept inside water

நீருக்குள் வைக்கப்பட்டுள்ள மின்துகள்கள் மற்றும் மூடிய பரப்பு.

A.\(80q / \epsilon_0\) B.\(q / 40\epsilon_0\) C.\(q / 80\epsilon_0\) D.\(q / 160\epsilon_0\)

Two identical conducting balls having positive charges \(q_1\) and \(q_2\) are separated by a centre to centre distance \(r\). If they are made to touch each other and then separated to the same distance, the force between them will be

A.less than before B.same as before C.more than before D.zero

Rank the electrostatic potential energies for the given system of charges in increasing order.

நான்கு மின்துகள் அமைப்புகள் (a), (b), (c), (d) காட்டப்பட்டுள்ளன.

A.\(1 = 4 < 2 < 3\) B.\(2 = 4 < 3 < 1\) C.\(2 = 3 < 1 < 4\) D.\(3 < 1 < 2 < 4\)

An electric field \(\vec{E} = 10x \hat{i}\) exists in a certain region of space. Then the potential difference \(V = V_o - V_A\), where \(V_o\) is the potential at the origin and \(V_A\) is the potential at \(x = 2 \text{ m}\) is:

A.\(10 \text{ V}\) B.\(-20 \text{ V}\) C.\(+20 \text{ V}\) D.\(-10 \text{ V}\)

Q10

A thin conducting spherical shell of radius \(R\) has a charge \(Q\) which is uniformly distributed on its surface. The correct plot for electrostatic potential due to this spherical shell is

கோளகக் கூட்டினால் ஏற்படும் மின்னழுத்தம் V க்கும் தொலைவு r க்கும் இடையேயான வரைபடங்கள்.

A.(a) B.(b) C.(c) D.(d)

Q11

Two points A and B are maintained at a potential of \(7 \text{ V}\) and \(-4 \text{ V}\) respectively. The work done in moving \(50\) electrons from A to B is

A.\(8.80 \times 10^{-17} \text{ J}\) B.\(-8.80 \times 10^{-17} \text{ J}\) C.\(4.40 \times 10^{-17} \text{ J}\) D.\(5.80 \times 10^{-17} \text{ J}\)

Q12

If voltage applied on a capacitor is increased from \(V\) to \(2V\), choose the correct conclusion.

A.\(Q\) remains the same, \(C\) is doubled B.\(Q\) is doubled, \(C\) doubled C.\(C\) remains same, \(Q\) doubled D.Both \(Q\) and \(C\) remain same

Q13

A parallel plate capacitor stores a charge \(Q\) at a voltage \(V\). Suppose the area of the parallel plate capacitor and the distance between the plates are each doubled then which is the quantity that will change?

A.Capacitance B.Charge C.Voltage D.Energy density

Q14

Three capacitors are connected in triangle as shown in the figure. The equivalent capacitance between the points A and C is

முக்கோண வடிவில் இணைக்கப்பட்ட மூன்று மின்தேக்கிகளின் மின்சுற்று.

A.\(1 \mu\text{F}\) B.\(2 \mu\text{F}\) C.\(3 \mu\text{F}\) D.\(14 \mu\text{F}\)

Q15

Two metallic spheres of radii \(1 \text{ cm}\) and \(3 \text{ cm}\) are given charges of \(-1 \times 10^{-2} \text{ C}\) and \(5 \times 10^{-2} \text{ C}\) respectively. If these are connected by a conducting wire, the final charge on the bigger sphere is

A.\(3 \times 10^{-2} \text{ C}\) B.\(4 \times 10^{-2} \text{ C}\) C.\(1 \times 10^{-2} \text{ C}\) D.\(2 \times 10^{-2} \text{ C}\)

Q16

Which specific branch of electricity deals with the behavior and study of stationary charges at rest?

A.Magnetostatics B.Electrostatics C.Electrodynamics D.Current Electricity

Q17

In the SI system of units, what is the approximate numerical value of the proportionality constant \(k\) used in Coulomb's law for free space?

A.\(9 \times 10^9\) N m\(^2\) C\(^{-2}\) B.\(8.85 \times 10^{-12}\) C\(^2\) N\(^{-1}\) m\(^{-2}\) C.\(1.6 \times 10^{-19}\) C D.\(6.63 \times 10^{-34}\) J s

Q18

What is the standard SI unit used to measure the intensity of an electric field?

A.Coulomb meter (C m) B.Newton per Coulomb (N C\(^{-1}\)) C.Joule per Coulomb (J C\(^{-1}\)) D.Volt meter (V m)

Q19

Why is it physically impossible for two electric field lines to intersect each other in a region of space?

A.Because they are always parallel to each other B.Because they would neutralize each other at that point C.Because the electric field would have two different directions at the same point D.Because field lines only exist in one dimension

Q20

What is the conventional direction assigned to the electric dipole moment vector?

A.From the positive charge to the negative charge B.Perpendicular to the axis joining the charges C.From the negative charge to the positive charge D.Radially outward from the midpoint

Q21

At very large distances \(r\) from a dipole, how does the electric field magnitude on the axial line compare to the field magnitude on the equatorial plane at the same distance?

A.They are exactly equal in magnitude B.The axial field is twice as strong as the equatorial field C.The equatorial field is twice as strong as the axial field D.The axial field is four times as strong

Q22

How is the electrostatic potential difference between two points P and R defined?

A.The work done by an external force to bring a unit positive charge from R to P B.The total electrostatic force acting between points R and P C.The product of the charge and the distance between the two points D.The potential energy stored in a single stationary point charge

Q23

What is the net work done when moving a test charge between any two points located on the same equipotential surface?

A.Maximum work is done B.Work depends on the path taken C.Zero work is done D.Work equals the product of charge and field

Q24

According to Gauss's law, on what factor does the total electric flux passing through a closed Gaussian surface solely depend?

A.The geometric shape and size of the surface B.The net electric charge enclosed within the surface C.The distribution of charges located outside the surface D.The velocity of the charges moving inside the surface

Q25

In the context of electrostatic shielding, what is the value of the electric field inside a cavity of a conductor?

A.It is equal to the external applied field B.It varies based on the shape of the cavity C.It is always zero D.It depends on the material of the conductor

Q26

What phenomenon occurs in a non-polar dielectric molecule when it is subjected to an external electric field?

A.It loses its electrons and becomes ionized B.Its positive and negative charge centers coincide more perfectly C.It acquires an induced dipole moment D.It begins to flow like a metallic conductor

Q27

The SI unit of capacitance, the Farad, is named in honor of which renowned scientist?

A.Charles Coulomb B.Alessandro Volta C.Michael Faraday D.James Clerk Maxwell

Q28

What is the effect on the capacitance of a parallel plate capacitor when a dielectric material with relative permittivity \(\epsilon_r\) is inserted between its plates?

A.The capacitance decreases by a factor of \(\epsilon_r\) B.The capacitance remains constant C.The capacitance increases by a factor of \(\epsilon_r\) D.The capacitance becomes independent of plate area

Q29

In an irregularly shaped charged conductor, why is the surface charge density highest at the regions with the sharpest points?

A.Because the surface area is largest at sharp points B.Because the radius of curvature is smallest at sharp points C.Because the electric potential is highest at sharp points D.Because air resistance is lowest at sharp points

Q30

Which two specific electrostatic phenomena are primarily utilized for the large-scale accumulation of charge in a Van de Graaff generator?

A.Dielectric breakdown and Joule heating B.Electrostatic induction and action of points C.Coulomb repulsion and Magnetic torque D.Dipole polarization and Ohmic conduction

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About this Electrostatics test

This free online practice test covers Electrostatics from the 12th Standard Physics (Samacheer Kalvi) syllabus. Choose the number of questions and an optional time limit, then answer and submit — everything is checked in your browser, with the correct answers and a worked explanation shown at the end. For the full solutions to every question in this set, see the solved MCQs page.

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