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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.
| 201. |
Figure shows a network of seven capacitors. The charge on the `5muF` capacitor si `10muC`. The potential difference between points `A` and `B`A. `2V`B. `4V`C. `6V`D. `8V` |
| Answer» Correct Answer - D | |
| 202. |
In the circuit in figure `emf E_(1) = 14V` (internal resistance `r_(1) = 1Omega`),`R_(1) = 6Omega R_(2) = 3.5 Omega, emf E_(2) = 12v` (internal resistance `r_(2) = 0.5Omega), C_(1) = 4muF` and `C_(2) = 2muF`. The potential difference across `R_(1)` isA. `2V`B. `12V`C. `14V`D. `26V` |
| Answer» Correct Answer - B | |
| 203. |
The dielectric to be used in a parallel-plate capacitor has a dielectric constant of 3.60 and a dielectric strength of `1.60 xx 10^7 V//m`. The capacitor is to have a capacitance of `1.25 xx10^-9F` and must be able to withstand a maximum potential difference of `5500 V`. What is the minimum area the plates of the capacitor may have? |
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Answer» Correct Answer - `0.0135m^(2)` |
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| 204. |
On placing a dielectric slab between the plates of an isolated charged condenser its -A. `{:(,"Capacitance","Charge","Potentlal Difference ","Energy stored","Electric field"),(,"decreases","remains","decreases","increases","increases"),(,,"unchanged",,,):}`B. `{:(,"Capacitance","Charge","Potentlal Difference ","Energy stored","Electric field"),(,"increases","remains","increases","increases","decreases"),(,,"unchanged",,,):}`C. `{:(,"Capacitance","Charge","Potentlal Difference ","Energy stored","Electric field"),(,"increases","remains","decreases","decreases","decreases"),(,,"unchanged",,,):}`D. `{:(,"Capacitance","Charge","Potentlal Difference ","Energy stored","Electric field"),(,"decreases","remains","decreases","increases","remains"),(,,"unchanged",,,"unchanged"):}` |
| Answer» Correct Answer - C | |
| 205. |
When a dielectric material is introduced between the plates of a charged condenser, after disconnected the battery the electric field between the platesA. increases while its capacity increasesB. increases while its capacity decreasesC. decreases while its capacity increasesD. decreases while its capacity decreases |
| Answer» Correct Answer - C | |
| 206. |
Figure shows a network of seven capacitors. The charge on the `5muF` capacitor si `10muC`. The potential differenc between points `A` and `C`A. `(16)/(3)V`B. `(12)/(5)V`C. `(8)/(3)V`D. zero |
| Answer» Correct Answer - A | |
| 207. |
The plates of charged condenser are connected by a conducting wire. The quantity of heat produced in the wire isA. Inversely proportional to the capacity of the condenserB. Inversely proportional to the square of the potential of the condenserC. Proportional to the length of wireD. independent of the resistance of the wire |
| Answer» Correct Answer - D | |
| 208. |
A `4muF` condenser is charged to `400V` and then its plates are joined through a resistance of `1KOmega`. The heat produced in the resistance is :A. `0.16J`B. `1.28J`C. `0.64J`D. `0.32J` |
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Answer» Correct Answer - D |
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| 209. |
A network of uncharged capacitors and resistances is as shown Current through the battery immediately after key K is closed and after a long time interval is :A. `(E)/(R_(1)), (E)/(R_(1)+R_(3))`B. `(E)/(R_(1)+R_(3)),(E)/(R_(1)+(R_(2) R_(3))/(R_(2)+R_(3)))`C. Zero, `(E)/(R_(1))`D. `(E)/(R_(1)+(R_(2)R_(3))/(R_(2)+R_(3))),(E)/(R_(1))` |
| Answer» Correct Answer - A | |
| 210. |
A capacitor `C` is connected to a battery circuit having two switches `S_(1)` and `S_(2)` and resistances `R_(1)` and `R_(2)`. The capacitor will be fully charged when .A. both `S_(1)` and `S_(2)` are closedB. `S_(1)` is closed and `S_(2)` is openC. `S_(1)` is open and `S_(2)` is closedD. any of the above |
| Answer» Correct Answer - B | |
| 211. |
A parallel plate capacitor has area of each plate `A`, the separation between the plates is `d`. It is charged to a potential `V` and then disconnected from the battery. The amount of work done in the filling the capacitor Completely with a dielectric constant `k` is.A. `(1)/(2)(epsilon_(0)AV^(2))/(d)[1-(1)/(k^(2))]`B. `(1)/(2)(V^(2) epsilon_(0)A)/(kd)`C. `(1)/(2)(V^(2)epsilon_(0)A)/(k^(2)d)`D. `(1)/(2)(epsilon_(0)AV^(2))/(d)[1-(1)/(K)]` |
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Answer» Correct Answer - D Work done = decrease in energy ie `w-E_(1)-E_(2)=(1)/(2)(epsilon_(0)A)/(d)v^(2)-(epsilon_(0)Av^(2))/(2d)[1-(1)/(k)]`. |
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| 212. |
Assertion: A parallel plate capacitor is charged to a potential difference `100 V`, and disconnected from the voltage source. A slab of dielectric is then slowly inserted between the plates. Compared to the energy before the slab was inserted, the energy stored in the capacitor with the dielectric is decreased. Reason: When we insert a dielectric the plates of a capacitor, the induced tend to draw in the dielectric into the field (just as neutral). we resist this force while slowly inserting the dielectric, and thus do negative work on the system, removing electrostatic energy from the system.A. Both A and R falseB. Both A and R true and R is not correct reason for AC. A is true and R is falseD. Both A and R are true and R is correct reason of A. |
| Answer» Correct Answer - A | |
| 213. |
Assertion. A metallic shield in the form of a hollow shell, can be built to block an electric field. Reason. In a hollow spherical shell, the electric field inside is not zero at every point.A. Both A and R falseB. Both A and R true and R is not correct reason for AC. A is true and R is falseD. Both A and R are true and R is correct reason of A. |
| Answer» Correct Answer - A | |
| 214. |
A capacitor of capacitance `C_(1)=1 muF` withstand a maximum voltage of `V_(1)=6 KV`, and another capacitor of capacitance `C_(2)=2 muF`, can with stand a maximum voltage of `V_(2)=4KV`. If they are connected in series, what maximum voltage will the system withstand?A. 3 kVB. 6 kVC. 10 kVD. 9 kV |
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Answer» Correct Answer - D `V_(1) le V_(max1), V_(2) le V_(max 2)`. |
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| 215. |
A capacitor of capacitance `C_(1)=1 muF` withstand a maximum voltage of `V_(1)=6 KV`, and another capacitor of capacitance `C_(2)=2 muF`, can with stand a maximum voltage of `V_(2)=4KV`. If they are connected in series, what maximum voltage will the system withstand?A. `6kV`B. `4kV`C. `10kV`D. `9kV` |
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Answer» Correct Answer - D |
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| 216. |
When two spheres carrying same charge but a different radii are connected by a conducting wire, the charge flows from smaller sphere to large sphere. Smaller sphere is at high potential when equal charges are imparted to both the spheres.A. Both A and R falseB. Both A and R true and R is not correct reason for AC. A is true and R is falseD. Both A and R are true and R is correct reason of A. |
| Answer» Correct Answer - D | |
| 217. |
Two capacitors are connected in parallel to a battery. If a dielectric medium is inserted between the plates of one of the capacitors then the enegry stored in the system will increase. On inserting dielectric medium between the plates of a capacitors, its capacity increases.A. Both A and R falseB. Both A and R true and R is not correct reason for AC. A is true and R is falseD. Both A and R are true and R is correct reason of A. |
| Answer» Correct Answer - D | |
| 218. |
Three capacitors are connected to `D.C` source of `100` volts shown in the adjoining figure. If the charge accumulated on plates of `C_(1), C_(2)` and `C_(3)` are `q_(a), q_(b), q_(c ), q_(d), q_(e)` and `q_(f)` respectively, then A. `q_(b)+q_(d)+q_(f)=(100//9)C`B. `q_(b)+q_(d)+q_(f)=0`C. `q_(a)+q_(c)+q_(e)=50C`D. `q_(b)=q_(d)=q_(f)` |
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Answer» Correct Answer - D |
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| 219. |
In the adjoining diagram two geometrically identical capacitors A and B are connected to a battery. Air is filled between the plates of `C_(1)` and a dielectric is filled between the plates of `C_(2)`, then - A. `q1 lt q2`B. `q1 gt q2`C. `q1=q2`D. None of these |
| Answer» Correct Answer - A | |
| 220. |
A parallel plate condenser is connected to a battery of e.m.f. 4 volt. If a plate of dielectric constant 8 is inserted into it, then the potential difference on the condenser will be -A. 1/2 VB. 2VC. 4VD. 32V |
| Answer» Correct Answer - C | |
| 221. |
One plate of parallel plate capacitor is smaller than the other, the charge on the smaller plate will be.A. less than otherB. more than otherC. equal to otherD. will depend upon the medium between them |
| Answer» Correct Answer - C | |
| 222. |
Two condensers of unequal capacities are connected in series across a constant voltage `d.c` source. The ratio of the potential difference across the condenser will be.A. direct proportion to their capacitiesB. inverse proportion to their capacitiesC. direct proportion to the square of their capacitiesD. inverse proportion to the square root of their capacities |
| Answer» Correct Answer - A | |
| 223. |
Two condensers `A` and `B` each having slabs of dielectric constant `K = 2` are connected in series. When they are connected across `230 V` supply, potential difference across `A` is `130 V` and that across B is `100 V`. If the dielectric in the condenser of smaller capacitance is replaced by one for which `K = 5`, what will be the values of potential difference across them? |
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Answer» Correct Answer - `78.68V, 151.32V` |
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| 224. |
Three condensers `1 mu F,2 mu F` and `3 mu F` are connected in series to a `p.d` of `330 " volt"`. The `p.d` across the plates of `3 mu F` is.A. 180 VB. 300 VC. 60 VD. 270 V |
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Answer» Correct Answer - C `Q=C_(eff)V Q =C_(1)V`. |
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| 225. |
Two condensers of unequal capacities are connected in series across a constant voltage `d.c` source. The ration of the potential difference across the condenser will be.A. direct proportion to their capacitiesB. inverse proportion to their capacitiesC. direct proportion to the square of their capacitiesD. inverse proportion to the square root of their capacities |
| Answer» Correct Answer - B | |
| 226. |
The condenser used in the tuning circuit of radio receiver is.A. paper condenserB. electrolytic condenserC. leygen jarD. gang condenser |
| Answer» Correct Answer - D | |
| 227. |
A parallel plate copacitor is first charged and then isolated, and a dielelctric slab is introduced between the plates. The quantity that remains unchanged is.A. Charge `Q`B. Potential `V`C. Capacity `C`D. Energy `U` |
| Answer» Correct Answer - A | |
| 228. |
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 field remains of 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 `E_(0-d) gt E_(d-2d)` (Conceptual). |
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| 229. |
A variable parallel plate capacitor and an electroscope are connected in parallel to a battery. The reading of the electroscope would be decreased by.A. Only(i), (ii) and (iii) are correctB. Only (i) and (ii) are correctC. Only(ii) and (iv) are correctD. Only (iv) is correct |
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Answer» Correct Answer - D |
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| 230. |
A battery is used to charge a parallel plate capacitor till the potential differece between the plates becomes equal to the electromotive force of the battery. The ratio of the energy stored in the capacitor and the work done by the battery will beA. 1B. 2C. `1//4`D. `1//2` |
| Answer» Correct Answer - D | |
| 231. |
The strength of electric filed in the charged and isolated capacitor is decreased when the dielectric slab is inserted. When the dielectric slab is inserted between the plates of a charged capacitor, electricfield produced due to induced charged, opposite to the external field.A. Both A and R falseB. Both A and R true and R is not correct reason for AC. A is true and R is falseD. Both A and R are true and R is correct reason of A. |
| Answer» Correct Answer - D | |
| 232. |
A parallel plate capacitor of capacitance 90 pF is connected to a battery of emf 20V. If a dielectric material of dielectric constant K=5/3 is inserted between the plates, the magnitude of the induced charge will be :A. 2.4 n CB. 0.9 n CC. 1.2 n CD. 0.3 n C |
| Answer» Correct Answer - C | |
| 233. |
Two idential capacitors are joined in parallel, charged to a potential `V` and then separated and then connected in series i.e. the positive plate of one is connected to negative of the otherA. the charge on the free plates are enhancedB. the charge on the free plates are decreasedC. the energy stored in the system increasesD. the potential difference between the free plates is `2V` |
| Answer» Correct Answer - D | |
| 234. |
A variable parallel plate capacitor and an electroscope are connected in parallel to a battery. The reading of the electroscope would be decreased by.A. increasing the area of overlap of the platesB. placing a block of paraffin wax between the platesC. decreasing the distance between the platesD. decreasing the battery potential |
| Answer» Correct Answer - D | |
| 235. |
A series combination of `n_(1)` capacitors, each of value `C_(1)`, is charged by a source of potential difference `4 V`. When another parallel combination of `n_(2)` capacitors, each of value `C_(2)`, is charged by a source of potential difference `V`, it has same (total) energy stored in it, as the first combination has. the value of `C_(2)`, in terms of `C_(1)`, is thenA. `(16C_(1))/(n_(1)n_(2))`B. `(2C_(1))/(n_(1)n_(2))`C. `16(n_(2))/(n_(2))C_(1)`D. `2(n_(2))/(n_(1))C_(1)` |
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Answer» Correct Answer - A `U=(1)/(2)(C_(1))/(n_(1))(4V)^(2)=(1)/(2)n_(2)C_(2)V^(2)` `C_(2)=(16C_(1))/(n_(1)n_(2))` |
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| 236. |
Three idential capacitors are combined differently. For the same voltage to each combination, the one that stores the greatest energy isA. the three in seriesB. the three in parallelC. two in series and the third in paralllel with itD. two in parallel and the third in series with it |
| Answer» Correct Answer - B | |
| 237. |
We have a combination as shown in following figure. Choose the correct options : A. The charge on each capacitor is `600 mu C`B. The potential difference between the plates of `C_(1)` is 30 VC. The potential difference between the plates of `C_(2)` is 20 VD. The potential difference between the plates of `C_(3)` is 40 V |
| Answer» Correct Answer - A::B::C::D | |
| 238. |
For the circuit shown in figure, which of the below options given is/are correct: A. The charge on the `12muF` capacitor is zeroB. The charge on the `12muF` capacitor is `30muC`C. The charge on thhe `4muF` capacitor is `30muC`D. None of these |
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Answer» Correct Answer - A |
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| 239. |
In the following circuit two identical capacitors, a battery and a switch (s) are connected as shown. The switch (s) is opened and dielectric of constant `(K=3)` are inserted in the condensers. The ratio of electrostatic energies of the system before and after filling the dielectric will be. .A. `3 : 1`B. `5 : 1`C. `3 : 5`D. `5 : 3` |
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Answer» Correct Answer - C `:. U_(1)=(1)/(2) CV^(2)+(1)/(2)CV^(2)=CV^(2)` `:. U_(2)=(1)/(2) xx3xxCV^(2) +(1)/(2) xx3C(V^(2))/(9)=(5)/(3) CV^(2)` `:. (U_(1))/(U_(2))=(3)/(5)`. |
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| 240. |
In the following circuit, the resultant capacitance between `A` and `B` is `1muF`. Then value of `C` is A. `32/11muF`B. `11/32muF`C. `23/32 muF`D. `32/23 muF` |
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Answer» Correct Answer - D |
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| 241. |
Two identical capacitors A and B shown in the given circuit are joined in series with a battery. If a dielectric slab of dielectric constant K is slipped between the plates of capacitor B and battery remains connected, then the energy of capacitor A will- A. DecreaseB. IncreaseC. Remain the sameD. Becomes zero |
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Answer» Correct Answer - B |
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| 242. |
Four condenser are joined as shown in the adjoining figure. The capacity of each is `8 muF`. The equivalent capacity between the points `A` and `B` will be A. `32muF`B. `2muF`C. `8muF`D. `16muF` |
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Answer» Correct Answer - A |
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| 243. |
A capacitor of capacitance of `2muF` is charged to a potential difference of `200V`, after disconnecting from the battery, it is connected in parallel with another uncharged capacitor. The final common potential is `20V` then the capacitance of second capacitor is :A. `2muF`B. `4muF`C. `18muF`D. `16muF` |
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Answer» Correct Answer - C |
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| 244. |
When a battery of emf `E` volts is connected across a capacitor of capacitance `C`, then after some time the potential difference between the plates of the capacitor becomes equal to the battery voltage. The ratio of the work done by the battery and the energy stored in the capacitor when it is fully charged isA. `1:1`B. `1:2`C. `2:1`D. `4:1` |
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Answer» Correct Answer - C |
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| 245. |
A parallel -plate capacitor with the plate area `100cm^2` and the separation between the plate `1.0cm` is connected across a battery of emf 24 volts .Find the force of attraction between the plates. |
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Answer» Correct Answer - `2.5xx10^(-7)N` |
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| 246. |
A parallel plate capacitor is made of two circular plates separated by a distance 5mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is `3xx10^4V//m` the charge density of the positive plate will be close to:A. `6xx10^(-7)C//m^(2)`B. `3xx10^(-7)C//m^(2)`C. `3xx10^(4)C//m^(2)`D. `6xx10^(4)C//m^(2)` |
| Answer» Correct Answer - A | |
| 247. |
Three parallel plate capacitors `C_(1) = 4 muF,C_(2) =2mu F,C_(3) = 6muF` with respective charges `q_(1) = 20 muC,q_(2) = 10 mu C,q_(3) =5 muC` are connected in series with a battery of `emf 10 V` through an open switch as shown. Now the switch is closed and steady state is reached. .A. The final charge on `C_(1) =30 muC`B. The final charge on `C_(2) = 20 muC`C. The final charge on `C_(2) = zero`D. The final charge on `C_(3) = 15 muC` |
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Answer» Correct Answer - A::C::D After the switch is closed, let a charge `Q` be driven by the battery. Now, new charges on capacitors would become, `Q_(1)=(20+Q)muC ,Q_(2)=(10-Q)muC` `Q_(3)=(5+Q)muC (20+Q)/(4)-(10-Q)/(2)+(5+Q)/(6) =10` `60+3Q-60+6Q +10+2Q=120` `11Q =110 , Q=10 muC`. |
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| 248. |
Three parallel plate capacitors `C_(1) = 4 muF,C_(2) =2mu F,C_(3) = 6muF` with respective charges `q_(1) = 20 muC,q_(2) = 10 mu C,q_(3) =5 muC` are connected in series with a battery of `emf 10 V` through an open switch as shown. Now the switch is closed and steady state is reached. .A. The final charge on `C_(1) = (210)/(11) mu C`B. The final charge on `C_(2) = (120)/(11) muC`C. The final charge on `C_(2) = zero`D. The final charge on `C_(3) = (45)/(11) muC` |
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Answer» Correct Answer - A::B::D Let the final charges on the capacitors be `q_(1),q_(2) &q_(3)` `(q_(1))/(4)+(q_(2))/(2)+(q_(3))/(6)=0`....(1) `q_(1)+q_(2)=-30` ....(2) `q_(1)-q_(3)=15` .....(3) solve these equations and get the answers. |
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| 249. |
In the circuit shown below, the key is pressed at time t = 0 . Which of the following statements (s) is (are) true? A. The voltmeter displays -5 V as soon as the key is pressed, and displays +5 V after a long timeB. The voltmeter will display 0 V at time t = ln 2 secondsC. The current in the ammeter becomes 1/e of the initial value after 1 secondD. The current in the ammeter becomes zero after a long time |
| Answer» Correct Answer - A::B::C::D | |
| 250. |
Consider the situation shown in the figure. The capacitor `A` has a charge `q` on it whereas `B` is uncharged. The charge appearing on the capacitor `B` a long `7` time after the switch is closed is : .A. zeroB. `q//2`C. `q`D. `2q` |
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Answer» Correct Answer - A As circuit is not closed, charge will not flow. |
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