InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The electric potential at a point in free space due to a charge `Q` coulomb is `Q xx 10^(11)` volts. The electric field at that point isA. `4 pi epsilon_(0)Q xx 10^(20) "Vm"^(-1)`B. `12 pi epsilon_(0)Q xx 10^(22) "Vm"^(-1)`C. `4 pi epsilon_(0)Q xx 10^(22) "Vm"^(-1)`D. `12 pi epsilon_(0)Q xx 10^(20) "Vm"^(-1)` |
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Answer» Correct Answer - C |
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| 2. |
The work done in placing a charge of `8xx10^-18` coulomb on a condenser of capacity 100 micro-farad isA. `16 xx 10^(-32) J`B. `31 xx 10^(-26) J`C. `4 xx 10^(-10) J`D. `32 xx 10^(-32)J` |
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Answer» Correct Answer - D |
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| 3. |
If `4 xx 10^(20)eV` energy is required to move a charge of `0.25` coulomb between two points. Then what will be the potential difference between them ?A. 178 VB. 256 VC. 356 VD. None of these |
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Answer» Correct Answer - B |
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| 4. |
The work done to move a charge along an equipotential from `A` to `B`A. cannot be defined as `-int_(A)^(B)E.dl`B. must be defined as `-int_(A)^(B)E.dl`C. is zeroD. can have a non-zero value |
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Answer» Correct Answer - C |
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| 5. |
The electric potential `V` at any point `(x,y,z)`, all in meters in space is given by `V= 4x^(2)` volt. The electric field at the point `(1,0,2)` in volt//meter isA. 8 along negative X-axisB. 8 along positive X-axisC. 16 along negative X-axisD. 16 along positive Z-axis |
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Answer» Correct Answer - A |
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| 6. |
The electric potential `V` is givne as a function of distance `x` (metre) by `V = (5 x^(2) + 10x - 9)` volt. Value of electric field at `x = 1 `isA. `-20 V//m`B. `6 V//m`C. `11 V//m`D. `-23 V//m` |
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Answer» Correct Answer - A |
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| 7. |
The work done in bringing a `20` coulomb charge from point `A` to point `B` for disatnce `0.2 m` is `2 J`. The potential difference between the two points will be (in volt)A. 0.2B. 8C. 0.1D. 0.4 |
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Answer» Correct Answer - C |
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| 8. |
As shown in the figure, charges `+q and -q` are placed at the vertices `B` and `C` of an isoscles triangle. The potential at the vertex `A` is A. `(1)/(4pi epsilon_(0)).(2q)/(sqrt(a^(2)+b^(2)))`B. zeroC. `(1)/(4pi epsilon_(0)).(q)/(sqrt(a^(2)+b^(2)))`D. `(1)/(4pi epsilon_(0)).(-q)/(sqrt(a^(2)+b^(2)))` |
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Answer» Correct Answer - B |
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| 9. |
A ball of mass `1g` and charge `10^(-8) C` moves from a point `A`. Where potential is `600` volt to the point `B` where potential is zero. Velocity of the ball at the point `B` is `20 cm//s`. The velocity of the ball at the point `A` will beA. `22.8 " cms"^(-1)`B. `228 " cms"^(-1)`C. `16.8 " ms"^(-1)`D. `168 " ms"^(-1)` |
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Answer» Correct Answer - A |
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| 10. |
If an electron moves from rest from a point at which potential is `50` volt to another point at which potential is `70` volt, then its kinetic energy in the final state will beA. `3.2 xx 10^(-10)J`B. `3.2 xx 10^(-18)J`C. 1 ND. 1 dyne |
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Answer» Correct Answer - B |
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| 11. |
If a positive charge is shifted from a low - potential region to a high- potential region, the electric potential energyA. increasesB. decreasesC. remains the sameD. may increase or decrease |
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Answer» Correct Answer - A |
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| 12. |
An electron initially at rest falls a distance of 1.5 cm in a uniform electric field of magnitude `2 xx10^(4) N//C`. The time taken by the electron to fall this distance isA. `1.3 xx10^(2) s`B. `2.1 xx10^(-2) s`C. `1.6xx10^(-10) s`D. `2.9xx10^(-9) s` |
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Answer» Correct Answer - D |
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| 13. |
In the circuit as shown in the figure the effective capacitance between `A` and `B` is A. `3 muF`B. `2 mu F`C. `4 mu F`D. `8 mu F` |
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Answer» Correct Answer - C |
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| 14. |
When a positive `q` charge is taken from lower potential to a higher potential point, then its potential energy willA. decreaseB. increaseC. remains changedD. become zero |
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Answer» Correct Answer - B |
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| 15. |
Four equal capacitors, each of capacity `C`, are arranged as shown. The effective capacitance between `A` and `B` is A. `(5)/(8)C`B. `(3)/(5)C`C. `(5)/(3)C`D. `C` |
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Answer» Correct Answer - C |
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| 16. |
In the figure shown, the effective capacitance between the points `A` and `B`, if each has capacitance `C`, is A. 2CB. C/5C. 5CD. C/2 |
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Answer» Correct Answer - A |
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| 17. |
A capacitor of `4 mu F` is connected as shown in the circuit. The internal resistance of the battery is `0.5 Omega`. The amount of charge on the capacitor plates will be . |
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Answer» Correct Answer - D |
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| 18. |
A uniform electric field E is created between two parallel ., charged plates as shown in figure . An electron . enters the field symmetrically between the plataes with a . speed `v_0. The length of each plate is l. Find the angle of . deviation of the path of the electron as it comes out . of the field. A. `theta="tan"^(-1)(El)/(mv_(0)^(2))`B. `theta=tan^(-1) ((e El)/(mv_(0)^(2)))`C. `theta=tan^(-1) ((e El)/(mv_(0)))`D. `theta=tan^(-1) ((e E)/(mv_(0)^(2)))` |
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Answer» Correct Answer - B |
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| 19. |
Two positive point charges of `12 mu C` and `8 mu C` are `10 cm` apart. The work done in bringing then `4 cm` closer isA. 5.8 JB. 5.8 eVC. 13 JD. 13 eV |
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Answer» Correct Answer - C |
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| 20. |
A particlem of mass `2 xx 10^(-3)` kg, charge `4 xx 10^(-3)C` enters in an electric field of `5 V//m`, then its kinetic energy after 10 s isA. 0.1 JB. 1 JC. 10 JD. 100 J |
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Answer» Correct Answer - C |
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| 21. |
If identical charges `(-q)` are placed at each corner of a cube of side `b`, then electric potential energy of charge `(+q)` which is palced at centre of the cube will beA. `(8sqrt(2)q^(2))/(4pi epsilon_(0)b)`B. `(-8sqrt(2)q^(2))/(pi epsilon_(0)b)`C. `(-4sqrt(2)q^(2))/(pi epsilon_(0)b)`D. `(-4 q^(2))/(sqrt(3)pi epsilon_(0)b)` |
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Answer» Correct Answer - D |
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| 22. |
Two positive point charges of 12 and 5 microcoulombs, are placed 10 cm apart in air. The work needed to bring them 4 cm closer isA. 3.6 JB. 2.6 JC. 4.8 JD. 6.0 J |
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Answer» Correct Answer - A |
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| 23. |
Four point charges `-Q, -q, 2q` and `2Q` are placed, one at each corner of the square. The relation between `Q` and `q` for which the potential at the centre of the square is zero isA. `Q=-q`B. `Q=-1/q`C. `Q=q`D. `Q=1/q` |
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Answer» Correct Answer - A |
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| 24. |
A mass `m=20 g` has a charge `q= 3.0 mC`. It moves with a velocity of 20 m/s and enters a region of electric field of 80 N/C in the same direction as the velocity of the mass. The velocity of the mass after 3 s in this region isA. 80 m/sB. 56 m/sC. 44 m/sD. 40 m/s |
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Answer» Correct Answer - B |
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| 25. |
Four idenbtial charges `+50 mu C` each are placed, one at each corner of a square of side `2 m`. How much external energy is required to bring another charge of `+50 mu C` from infinity to the centre of the square (Given `(1)/(4pi epsilon_(0)) = 9 xx 10^(9)(Nm^(2))/(C^(2)))`A. 64 JB. 41 JC. 16 JD. 10 J |
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Answer» Correct Answer - A |
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| 26. |
A particle of mass 2 g and charge `1 muC` is held at rest on a frictionless surface at a distance of 1m from a fixed charge of 1 mC. If the particle is released it will be repelled. The speed of the particle when it is at distance of 10 m from fixed charge is :A. `10 "ms"^(-1)`B. `20 "ms"^(-1)`C. `60 "ms"^(-1)`D. `90 "ms"^(-1)` |
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Answer» Correct Answer - D |
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| 27. |
Two spheres A and B of radius 4 cm and 6 cm are given charges of `80 muC and 40 muC`, respectively. If they are connected by a fine wire, then the amount of charge flowing from one to the other isA. `20 muC` from A to BB. `20 muC` from B to AC. `32 muC` from B to AD. `32 muC` from A to B |
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Answer» Correct Answer - D |
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| 28. |
Three charges are placed at the vertices of an equilateral triangle of side 10 cm. Assume `q_(1)=1 muC,q_(2)=-2 muC and q_(3)=4 muC`. Work done in separating the charges to infinity isA. `-4.5 J`B. `4.5 J`C. 45 JD. None of these |
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Answer» Correct Answer - D |
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| 29. |
Point charge `q_(1) = 2 mu C` and `q_(2) = - 1mu C` are kept at points `x = 0` and `x = 6` respectively. Electrical potential will be zero at pointsA. `x=2 and x=9`B. `x=1 and x=5`C. `x=4 and x=12`D. `x=-2 and x=2` |
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Answer» Correct Answer - C |
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| 30. |
The potential of a large liquid drop when eight liquid drops are combined is 20 V. Then, the potential of each single drop wasA. 10 VB. 7.5 VC. 5 VD. 2.5 V |
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Answer» Correct Answer - A |
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| 31. |
Eight oil drops of same size are charged to a potential to 50 V each. These oil drops are merged into one single larged drop. What will be the potential of the large drop ?A. 50 VB. 100 VC. 200 VD. 400 V |
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Answer» Correct Answer - C |
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| 32. |
A series combination of three capacitors of capacities `1 muF, 2muF` and `8 muF` is connected to a battery of e.m.f. `13 volt`. The potential difference across the plates of `2 muF` capacitor will beA. 1 VB. 8 VC. 4 VD. `(13)/(3) V` |
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Answer» Correct Answer - C |
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| 33. |
Eight small drops, each of radius `r` and having same charge q are combined to form a big drop. The ratio between the potentials of the bigger drop and the smaller drop isA. `8:1`B. `4:1`C. `2:1`D. `1:8` |
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Answer» Correct Answer - B |
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| 34. |
A number of capacitors each of capacitance `1 muF` and each one of which get punctured if a potential difference just exceeding `500` volt is applied, are provided. Then an arrangement suitable for giving a capacitor of `2 muF` across which `3000` volt may be applied requires at least-A. 6 component capacitorsB. 12 component capacitorsC. 72 component capacitorsD. 2 component capacitors |
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Answer» Correct Answer - C |
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| 35. |
A spherical drop of capacitance `1 muF` is broken into eight drop of equal radius. Then, the capacitance of each small drop isA. `1/2 muF`B. `1/4 muF`C. `1/8 muF`D. `8 muF` |
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Answer» Correct Answer - A |
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| 36. |
In the given figure the capacitors `C_(1), C_(3), C_(4),C_(5)` have a capaciance `4 muF` each if the capaitor `C_(2)` has a capacitance `10 muF`, then effective capacitance between `A` and `B` will be A. `2 muF`B. `4 mu `C. `6 muF`D. `8 muF` |
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Answer» Correct Answer - B |
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| 37. |
The capacitance of a metallic sphere is `1 muF`, if itsA. 9 kmB. 10 mC. 1.11 mD. 1.11 cm |
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Answer» Correct Answer - A |
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| 38. |
A parallel plate condenser has a capacitance `50 muF` in air and `100 muF` when immersed in an oil. The dielectric constant `k` of the oil isA. 0.45B. 0.55C. `1.10`D. `2.20` |
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Answer» Correct Answer - D |
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| 39. |
A parallel plate capacitor has plate separation d and capacitance `25 muF`. If a metallic foil of thickness `(2)/(7)d` is introduced betwenn the plates, the capacitance would becomeA. `25 muF`B. `35 muF`C. `(125)/(7)muF`D. `(175)/(2)muF` |
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Answer» Correct Answer - B::C |
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| 40. |
The capacitance of a parallel plate capacitor is `12 muF`. If the distance between the plates is doubled and area is halved, then new capacitance will beA. `8 muF`B. `6 muF`C. `4 muF`D. `3 muF` |
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Answer» Correct Answer - D |
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| 41. |
Consider a disconnected. Plate capacitor of capacity `10 muF` with air filled in the gap between the plates. Now one-half of the space between the plates is filled with a dielectric of dielectric constant `4` as shown in .The capacity of the capacitor changes to .A. `25 mu F`B. `20 muF`C. `40 muF`D. `5 muF` |
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Answer» Correct Answer - A |
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| 42. |
In a parallel plate capacitor, the separation between the plates is 3mm with air between them. Now a 1mm thick layer of a material of dielectric constant 2 is introduced between the plates due to which the capacity increases. In order to bring its capacity of the original value, the separation between the plates must be made-A. 1.5 mmB. 2.5 mmC. 3.5 mmD. 4.5 mm |
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Answer» Correct Answer - C |
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| 43. |
A dielectric slab of thickness `d` is inserted in a parallel plate capacitor whose negative plate is at `x=0` and positive plate is at `x = 3d`. The slab is equidistant from the plates. The capacitor is given some charge. As one goes from `0` to `3d(1998)`.A. the magnitude of the electric field remains the sameB. the direction of the electric remains the sameC. the electric potential increases continuouslyD. the electric potential increases at first, then decreases and again increases |
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Answer» Correct Answer - B::C |
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| 44. |
Separation between the plates of a parallel plate capacitor is `d` and the area of each plates is `A`. When a slab of material of dielectric constant `k` and thickness `t(t lt d)` is introduced between the plates. Its capacitance becomesA. `(epsilon_(0)A)/(d+t(1-(1)/(K)))`B. `(epsilon_(0)A)/(d+t(1+(1)/(K)))`C. `(epsilon_(0)A)/(d-t(1-(1)/(K)))`D. `(epsilon_(0)A)/(d-t(1+(1)/(K)))` |
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Answer» Correct Answer - C |
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| 45. |
The charge on any of the `2 muF` capacitors and `1 muF` capacitor will be given respectively (in `muC`) as A. 1, 2B. 2, 1C. 1, 1D. 2, 2 |
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Answer» Correct Answer - D |
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| 46. |
The potential enery of a charged parallel plate capacitor is `U_(0)`. If a slab of dielectric constant K is inserted between the plates, then the new potential energy will beA. `(U_(0))/(k)`B. `U_(0)k^(2)`C. `(U_(0))/(k^(2))`D. `U_(0)^(2)` |
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Answer» Correct Answer - A |
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| 47. |
A parallel plate capacitor of capacitance C is connected to a battery and is charged to a potential difference V. Another capacitor of capacitance 2C is ismilarly charged to a potential difference 2V. The charging battery is now disconnected and the capacitors are connected in parallel to each other in such a way that the poistive terminal of one is connected to the negative terminal of the other. The final energy of the configuration isA. zeroB. `(25 CV^(2))/(6)`C. `(3 CV^(2))/(2)`D. `(9 CV^(2))/(2)` |
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Answer» Correct Answer - C |
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| 48. |
A thin metal plate `P` is inserted between the plates of a parallel-plate capacitor of capacitance `C` in such a way that its edges touch the two plates (figure 31-Q2).The capacitance now becomes. A. C/2B. 2CC. zeroD. `infty` |
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Answer» Correct Answer - D |
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| 49. |
If there are n capacitors in parallel connected to V volt source, then the energy stored is equal toA. `nCV^(2)`B. `(1)/(2)nCV^(2)`C. `(CV^(2))/(n)`D. `(1)/(2n)CV^(2)` |
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Answer» Correct Answer - B |
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| 50. |
A network of four capacitors of capacity equal to `C_(1) = C, C_(2) = 2C, C_(3) = 3C` and `C_(4) = 4C` are connected to a battery as shown in the figure. The ratio o fthe charges on `C_(2)` an `C_(4)` is A. `22/3`B. `3/22`C. `7/4`D. `4/7` |
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Answer» Correct Answer - B |
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