83 free MCQs on Electrostatic Potential and Capacitance, each with its own worked answer and explanation. Electric potential, equipotential surfaces, potential energy of charge systems, conductors, dielectrics, capacitors, combinations, and energy storage.
Take the timed Electrostatic Potential and Capacitance chapterwise test →83 practice questions on Electrostatic Potential and Capacitance, sorted Easy → Hard. Try each one first, then open its answer page for the worked explanation. Want the full theory first? Read the Electrostatic Potential and Capacitance notes.
Field lines (radial) and equipotential lines (concentric circles) of a point charge. Equipotential surfaces are always perpendicular to the field lines. Image: Sjlegg, Public Domain, via Wikimedia Commons.
Q1.
1 electron-volt (eV) is equal to:
Q2.
The equipotential surfaces around an isolated point charge are:
Q3.
Inside a charged hollow spherical conductor, the electric potential is:
Q4.
The capacitance of an isolated spherical conductor depends only on its:
Q5.
When placed in an external electric field, a dielectric becomes:
Q6.
Work done to move charge q through potential difference V is:
Q7.
A capacitor stores:
Q8.
Capacitance formula for parallel plate capacitor (area A, gap d):
Q10.
Gauss's law relates electric flux through a closed surface to:
Q11.
Dielectric constant of vacuum is:
Q12.
If two capacitors of C each are connected in parallel, equivalent capacitance:
Q13.
Energy stored in a capacitor C at voltage V:
Q14.
A point charge of 2 C is placed at the center of a sphere of radius 1 m. Electric flux through sphere:
Q15.
Electric potential at a point is the work done per unit ___ in bringing a charge from infinity to that point:
Q16.
The SI unit of electric potential is the:
Q17.
Electric potential is a ___ quantity:
Q18.
The potential difference between two points is measured using a:
Q19.
A capacitor is a device that stores electric:
Q21.
The capacitance of a conductor is the ratio of its charge to its:
Q22.
Electric potential energy is measured in:
Q23.
By convention, the electric potential at infinity is taken to be:
Q24.
A surface on which every point is at the same potential is called an:
Q25.
The work done in moving a charge along an equipotential surface is:
Q26.
Four equal point charges of +2 µC are fixed at the corners of a square of side 0.1 m. The electric potential at the centre of the square is:
Q27.
Two isolated conducting spheres of radii 2 cm and 4 cm carry equal charges. When they are joined by a thin wire, charge flows from:
Q28.
The energy density in a region where the electric field is 2 × 10<sup>5</sup> V/m is (ε<sub>0</sub> = 8.85 × 10<sup>-12</sup>):
Q29.
The charge stored on a 5 µF capacitor charged to 200 V is:
Q30.
Two capacitors of 3 µF and 6 µF are joined in series across 9 V. The potential difference across the 3 µF capacitor is:
Q31.
Electric potential at a point due to 2 charges q<sub>1</sub>=+3 nC at 1 m and q<sub>2</sub>=-3 nC at 1 m (equal distances, same point):
Q32.
A capacitor C<sub>1</sub> = 4 microF and C<sub>2</sub> = 6 microF in series. Equivalent capacitance:
Q33.
Potential difference across 6 microF capacitor in series combination with 4 microF across 10 V:
Q34.
Electrostatic force F acts between two charges. If one charge doubles and separation halves, new force:
Q35.
Energy stored in a 10 microF capacitor charged to 100 V:
Q36.
Relation between electric field E and electric potential V:
Q37.
If dielectric of constant K is inserted in a parallel plate capacitor (isolated, constant charge Q), energy stored:
Q38.
Two conducting spheres of same charge Q but different radii r and 2r are connected by wire. Charge redistributes so:
Q39.
Potential energy of a system of two charges q<sub>1</sub> and q<sub>2</sub> separated by r:
Q40.
A test charge +q placed in a field has force F on it. Electric field is:
Q41.
Electric flux through a surface is maximum when the surface is _____ to the field:
Q42.
Electric potential at midpoint between two equal opposite charges (+Q and -Q) separated by 2d:
Q43.
A charge is placed at corner of a cube. What fraction of total flux passes through the cube?
Q44.
Capacitors C<sub>1</sub>=2 microF and C<sub>2</sub>=3 microF are in parallel across 12 V. Charge on C<sub>1</sub>:
Q45.
Electric potential energy gained by charge q accelerated through V volts:
Q46.
The electric potential due to a point charge q at a distance r is:
Q47.
The energy stored in a capacitor of capacitance C charged to voltage V is:
Q48.
For two capacitors connected in parallel, the equivalent capacitance is:
Q49.
For a parallel-plate capacitor C = ε₀A/d, increasing the plate separation d causes the capacitance to:
Q50.
Inserting a dielectric slab between the plates of a capacitor causes its capacitance to:
Q51.
A 6 µF capacitor is charged to 100 V and then disconnected from the battery. A dielectric slab of constant 2 is inserted fully. The energy now stored is:
Q52.
Two 4 µF capacitors are connected in series, and this combination is joined in parallel with a 2 µF capacitor. The equivalent capacitance is:
Q53.
A 2 µF and a 3 µF capacitor are connected in parallel and charged to 100 V. The total energy stored is:
Q54.
A parallel plate capacitor stays connected to a battery of constant voltage. A dielectric of constant 3 is inserted. The charge on the plates:
Q55.
A charged parallel plate capacitor is disconnected from the battery, then a dielectric of constant K is inserted. The potential difference across it:
Q56.
Three capacitors 1, 2, 3 microF in series across 11 V. Charge on 3 microF:
Q57.
In Millikan's oil drop experiment, an oil drop is stationary. This means:
Q58.
Energy stored in an electric field of intensity E in volume V (epsilon<sub>0</sub> is permittivity):
Q59.
Dielectric is inserted into a capacitor connected to a battery (constant voltage V). Energy stored:
Q60.
A particle of charge q and mass m is accelerated through potential V. De Broglie wavelength:
Q61.
Two metal spheres of different radii are connected by a long thin wire. Surface charge density:
Q62.
Electric flux through a hemisphere of radius R placed in uniform field E (flat face perpendicular to E, field going through flat face):
Q63.
Potential at center of a square with charges +Q at two adjacent corners and -Q at other two (side a):
Q64.
Relation between electric field E and potential V for a uniform field in x-direction:
Q65.
n identical capacitors each of capacitance C are connected first in series, then in parallel. Ratio of energy stored for same charge Q:
Q66.
A charge q is placed at center of a cube of side L. Electric flux through one face:
Q67.
Potential difference required to accelerate an electron from rest to 1% speed of light (m<sub>e</sub> = 9.1 x 10<sup>-31</sup> kg, c = 3 x 10<sup>8</sup> m/s):
Q68.
A parallel plate capacitor is charged and disconnected. One plate is moved to double the gap. Energy stored:
Q69.
Electric potential due to a dipole (p) at distance r at angle theta from dipole axis:
Q70.
If all charges are scaled up by factor k and all distances scaled up by factor d, electrostatic energy scales by:
Q71.
For two capacitors in series, the equivalent capacitance satisfies:
Q72.
Two 4 μF capacitors connected in series give an equivalent capacitance of:
Q73.
Two 4 μF capacitors connected in parallel give an equivalent capacitance of:
Q74.
Since E = −dV/dx, the electric field points in the direction of ___ potential:
Q75.
A 2 μF capacitor charged to 100 V stores an energy of:
Q76.
Two capacitors of 2 μF and 3 μF are connected in series. Their combined capacitance is:
Q77.
A parallel-plate capacitor is fully filled with a dielectric of constant 4. Its capacitance compared with the air-filled value becomes:
Q78.
A 2 μF capacitor is charged to 100 V. The energy stored in it is:
Q79.
A charged parallel-plate capacitor is disconnected from the battery, then the plate separation is doubled. The stored energy:
Q80.
The electric potential at 2 m from a point charge of 2 nC is (k = 9×10⁹):
Q81.
A 4 μF capacitor charged to 100 V is connected in parallel to an identical uncharged 4 μF capacitor. The common final voltage is:
Q82.
The work done in moving a charge between two points at the same electric potential is:
Q83.
The capacitance of an isolated conducting sphere of radius R is 4πε₀R. If the radius is doubled, the capacitance:
or take the timed test and get a score instead of just reading