Capacitors Questions and Answers

40 In the circuit below C 20 F C 40 F and C3 50 F If no capacitor can sustain more than 50 V then maximum potential difference between X and Y is q cu XHHY C 1 95 V 21 150 V C C3 2 75 V 4 65 V

In the circuit shown in figure the capacitors are initially uncharged The current through resistor PQ just after closing the switch is B 2A from Q to P D zero A 2A from P to Q C 6A from P to Q 652 2 F 50 amm 12V 192 4 F www 60

In the circuit shown in figure the switch S is initially open and both the capacitors are initially uncharged Switch S is closed at t 0 then S i at t 0 is i at t 0 is i att R V 3R V 4R is V 4R C 6R Electrostatic potential energy stored in the 27CV

P Capacity will become two time Q Charge stored in capacitor wil become two times 2 Distance between capacitor plates is halved R Energy stored in capacitor wi become two times 1 A electric slab of dielectric constant K 2 is completely filled between the plates r question 19 true a P Q only b Q R only 5 None

Let dielectric strength and dielectric constant be X and K respectively Then for a material used as dielectric in capacitor must have 1 high K and low X 3 low K and low X 2 high K and high X 4 low K and high X

ds a aving Deed can ance e Electrostatic Potential and Capacitance 103 A parallel plate capacitor has an electric field of 105V m between the plates If charge on the capacitor is 1 C then force on each of the plates is 1 0 5N 3 0 005N 2 0 05N 4 None

er ht al II 105 A parallel plate air cored capacitor has a capacitance C When it is half filled with a dielectric of dielectric constant 5 as shown in figure the increase in the capacitance is 401 1 400 33 3 per 2 66 6 4 200

2S 56 A parallel plate air capacitor is charged and ther disconnected from battery When a dielectric materia is inserted between the plates of the capacitor ther which of the following does not change 1 Electric field between the plates 2 Potential difference across the plates 3 Ratio of electric field in the region and potentia difference between plates 4 Energy stored in the capacitor

63 An insulator plate is passed through the plates of a capacitor as shown in the figure below Then current outside the capacitor A B 1 First flows from A to B and then from B to A 2 First flows from B to A and then from A to B 3 Always flows from B to A 67

charge In oscillating LC circuit the total stored energy is U and maxi upon capacitor is Q When the charge upon the capacitor is the energy stored in the inductor is O NIC O DIC

36 If the energy of a 100 F capacitor charged to 6 kV could all be used to lift a 50 kg mass then what would be greatest vertical height through which mass could be raised 1 0 6 mm 3 1 2 mm 2 3 6 m 4 12 m

50 In the given circuit the potential difference between points A and B is 18 V and charge on 2 F capacitor is 24 C The value of C is A 6 F HI 1 1 F 3 3 uF 2 F HI C HH 2 2 F 4 4 F B

Aakash Institute 53 The work done by the battery in uJ in charging the capacitors to steady state is 3u F 1 240 3 250 2 F TH 3 F 10V 2 F 2 1005 4 Zero 58 59

1 P 3 10uF 18 A parallel plate capacitor having a plate separation of 2mm is charged by connecting it to a 400V supply The energy density is 1 0 09 Jim 3 0 36 J m A charge is q kept in front of neutral metallic sphere as shown in the figure The value of electric field at the centre of sphere due to induced charge on surface of sphere is R 19 1 41 o k 1 1 Q k are ined as shown in the figure apacitor is 8pF Equivalent and B lp 1 2mm Q k 1 Q 2k 2 2 2 0 18 J m 4 0 72 J m 2 3 4neo R d 20 Two identical capacitors 1 and 2 are connected in series The capacitor 2 contains a dielectric slab of constant k as shown They are connected to a battery of emf vo volt The dielectric slab is then removed Let Q and Q be the charge stored in capacitor before removing the slab and Q and Q be the values after removing the slab Then 9 4n do 4 3q 41 o R 8 F 32pF R Q k 1 2 NIX 4 Q 3 1 In the arrangement the value of each capacitor is Xu F Then the equivalent capacitance between point a and c is In F 3 4 49 22 in the given arrangement the valu capacitance between points A and Bis 24 etquestionpaper 1 4pF 3 2uF 23 A solid sphere conducting is surrounded by metallic shell of radius 2r Initial charges on them are 5uC and 3 C respectively If both are connected by thin metallic wire then charge appearing on A and B are 1 4 C each 3 3 C and 5uC 1 3 1 2pF 0 K 1 KV K 1 7 B 5 C 2 0 and 8uC 4 2 C and 6uC There are two identical capacitors The first one is uncharged and filled with dielectric constant K while the other is charged to potential V having air between its plates If two capacitors are joined end to end the common potential wire be 2r 2 BuF 4 3uF 3 C 2 3 4 K 1 25 An uncharged sphere of metal is placed in a uniform electric field produced by two oppositely charge large plates The lines of force appear as Tall 1181 KV 2

Two connected bodies having respective capacitance C1 and C2 are charged with a total charge Q The potentials of the two bodies are 1 Q O C C C C Q QQ Q 2 C C C C 3 C C C C C C C C C

A spherical capacitor with radii a 8 cm b 12 cm is filled by dielectric with constant K 4 8 If the capacitor carries the charge 4 pC and the point P is at the midway between two plates r 10 cm the electric field at point P has the magnitude in V m

two capacitor of capacitance of 2 micro farad and 4 micro farad are connected in series outer pla te of 1st capacitor is at 600 V and outer plate of 2 nd capacitor is earthed potential of inner plate of each capacitor is answer is 200 V how

A capacitor of capacitance C is charged by connecting it to a battery of EMF E the capacitor is now disconnected and reconnected to a battery with polarity reversed calculate the heat

Capacitor of capacitance 2 microfarad and 3 microfarad is charged to potential difference of 12 volt and 6 volt respectively are connected in series to an uncharged capacitor of capacity 4 microfarad such that the like plates of the charged capacitor are together Find final charge on each capacitor

the circuit shown all capacitors are initially uncharged and switch S is closed at r 0 Charge on capacitor C at steady state is nuC Find the value of n 192 nswer 10 102 10 V 102 202 HH C 1 F 54 1 6 11 16 21 26 Not E E 1 1 N 13

Charges q q2 are placed on capacitors of capacitance C and C respectively arranged in series as shown Switch S is then closed What are the final charges q and q on the capacitors Given q 30 c q 20 c C 10 F C 20 F and 12 Volts C 41 q S 9 a

In the circuit shown all capacitors are initially uncharged and switch S is closed at t 0 Charge on capacitor C at steady state is n C Find the value of n 1923 192 122 10 V 122 292 292 192 www 292 192 1 92 192 S

10 C H MQ 200 V 550 V very high 49 The circuit shown consists of two identical capacitor 10 uF each a 1 0 MQ resistor three ideal voltage sources of terminal voltages 100 V 550 V 200 V and three switches Calculate amount of heat dissipated in the resistor over a long time after all the switches are closed simultaneously Ams 1 65 ones Cisconnected

In the circuit shown in figure reading of voltmeter is 80 V when only S is closed Reading of voltmeter is V when only S is closed and reading is V3 when both S and S are closed If R 12 Q and resistance of voltmeter is Ry then R Rv 48 Q 120 V V 90 V V3 75 8 V 4R V3 80 V 12R V S

A capacitor of capacitance C charge with Qo now it connected across a battery of e m f Qo V C such that positive plate of capacitor connected with ve end of battery and ve plate with ve end of battery then find energy supplied by battery before steady state condition obtained to capacitor is 2 1 3 2 C 4 20 2Q

Hi there I m Harsh Vadher Teaher here when I calculated for heat lo ss Energy stored in capacitor the n at the t I got Energy 0 becau se AVoltage 0 so I concluded that finally they would bear some simil ar charges So the solution is calc ulated with initially Energy stored is it right 1 2CeqAV where V loR flows fro m 1 and V2 has 0 correct A charged capacitor C is being discharged through a resistance R by putting switch 5 inculate the amount of heat liberated in R starting from this instant Also calculate current i through the 1 When the discharging current reduces to i switch is suddenly shifted to position 2 Calculate circuit as a function of time initially C is uncharged B R C

If the plates of a parallel plate capacitor are not equal in area then quantity of cha 1 On the plates will be same but nature of charge will differ 2 On the plates as well as nature of charge will be different 3 On the plates will be different but nature of charge will be same 4 As well as nature of charge will be same

B J t Vo Reading of voltmeters will be equal at 2RC In 4 3 Reading of voltmeters will be equal at RC In 4 3 At t 0 reading of voltmeter B is Vo Reading of voltmeter B varies from

Sir aapne kon sa phase 1 2 3 or 4 mana hai mujhe samajn nhi aa rha please diagram kay through samjha dijiye isko How can we simply understand this diagram given in quest ion please tell me For the circuit as shown in the figure the net charge on upper plate will be Area of each plate is A and separation between two consecutive plates is d 2 AV d AV 2d Zero Answer Find attachment let the perter are A and C This is an arrangement of two capacitors first we identify how capacitors are connected from a capacitor out The faces I and x volts and of which i is connected to 2 is grounded similarly faces 3 and which I i to form capacitor out grounded and u is connected to u vidlik the strangement is a capacitors in paralled So we have o CV V

2 capacitance Terminals ical capacitors C and C of equal are connected as shown in the circuit a and b of the key k are connected to charge capacitor C using battery of emf V volt Now disconnecting a and b the terminals b and c are connected Due to this what will be the percentage loss of energy V 01 a 0 02 NEET 2019 Odisha 1 25 2 75 3 0 4 50 The electrostatic force between the metal plates of k 30 C C figure c 2 In all the same 3 Minimur figure a A 4 Maxim figure A parallel d and ca material k as sh materia C in th given

It C and C are already charged to V 10V and V 20 V then find the charge flown through switch when it is closed 1 100 3 HC 3 100 C HF C 2uf V 10V S t 0 31 C 4uf V 20V 40V 200 3 4 200 C 2 C

Two identical capacitor C and C are connected in series with a battery They are fully charged now a dielectric slab is inserted between the plates of C The potential diff across C will C CC C 1 Increase 2 Decrease 3 Remain same V

Four very large metal plates are given the charges as shown in the figure The middle two are then connected through a wire Find the charge that will flow through the wire 20 Q 3Q 4Q THI A B 1 5Q A to B side 5Q 2 A to B side 3 5Q B to A side 4 No charge will flow

A neutral capacitor of capacitance C is connected to two voltmeters A and B Resistance of voltmeter A is 2R and voltmeter B is R If switch S is closed at t 0 then S B V A C Reading of voltmeters will be equal at t 2RC In 4 3 RC Reading of voltmeters will be equal at t In 4 3 At t 0 reading of voltmeter B is Vo

10 Calculate the Capacitance C Charge Q and Voltage V for each capacitor Draw all the necessary equivalent circuits write all your work and fill the table with your answers 24V C1 C3 C2 C4 CIF C 2 C 4 C 6 C 3 Cs 8 QICI Qi Q Q4 Qs VIVI VI V V VA Vs

52 Each of two large conducting parallel plates has one sided surface area A If one of the plates is given a charge Q whereas the other is neutral then the electric field at a point in between the plates is given by Q 1 A o Q Q 2 2A80 4 Zero

A shell of radius 1m is coated with a thin layer of B active material It s initial charge is zero and initial number of active atoms is x 10 2 If half life of 4 3 decay is 1 8 hr and all the electron are emitted with an energy of 1 44 keV find the time in hr after which charge on the sphere becomes constant Neglect the time taken by electron to return back

A 600 pF capacitor is charged by a 200 V supply It is then disconnected from the supply and is connected to another uncharged 300 pF capacitor Calculate how much electrostatic energy is lost in the process What is the source of energy loss

a What is the direction of flow of electron in a conductor and why b Define one coulomb c Which one is greater 100 C or 1000 m C and by how much d Find the total current flowing in the given circuit IV 4V www 95

conne plate The 3 6 V 4 3 5 V 42 A parallel plate capacitor after charging is kept connected to a battery and the plates are pulled apart with the help of insulating handles Now which of the following quantities will decrease 1 Charge 2 Capacitance 3 Energy stored 4 All of these Aakash Educational Services Limited Regd Office Aakash Tower 1 3

2 300 V 4 100 V A 3 F capacitor is charged to a potential of 300 V and 2 F capacitor is charged to 200 The capacitors are then connected in parallel with plates of opposite polarity joined togeth What amount of charge will flow when the plates are so connected 1 600 C 2 800 C 3 700 C 4 300 C

The gap between the plates of a plane capacitor is filled with an isotropic insul ator whose di electric constant varies in the direction perpendicular to t he plates according to the law K K1 1 sin x d XXX where d is the separation between the plates and K1 is a constant The area of the plates is S Determine the capacitance of the capacitor 5 Five identical conducting plates 1 2 3 4 and 5 are fixed parallel to and equid

NEET AIIMS me area are placed as given ation between any two and capacitance is C then S 50 B B EET AIIMS In the given circuit the charge stored in 2 F capacitor is 2 F 110 V 1 F 5 V F 44 Find the potential of 1 5 C 2 20 C 3 10 C 4 5 C 41 Area of one side of each plate is A and separation 10 V A HH 45 2 F 1 7 5 V 2 15 V 3 5 V 4 Zero A parallel

12 In the circuit shown there is steady state with the switch closed The switch is opened at t 0 Choose the correct option s Given 24V C 3F and C 2F 392 992 C S C 69 A The voltage across C before the switch is open is 12V B The voltage across C after a long time after the switch is open is 12V C The voltage across C after a long time after the switch is open is 24V D The voltage across C before the switch is open is 8V

A B C D E and F are conducting plates each of area A and any two consecutive plate with separation d The net energy stored in system after the switch S is closed is 38 AV A 3d B JOOL V 58 AV 12d C AV ad D AV d

7A capacitor of capacitance 5 00 uF is charged to 24 0 V and another capacitor of capacitance 6 0 uF is charged to 120 V a Find the energy stored in each capacitor b The positive plate of the first capacitor is now connected to the negative plate of the second and vice versa Find the new charges on the capacitors c Find the loss of electrostatic energy during the process d Where does this energy go

In the circuit Figure E 5 V r 1 ohm R 4 ohms R 3 ohms and C 3 F Find the charge on the pl capacitor A in C R R R C C Options C HH C

The plates of a parallel plate capacitor are pulled apart with a velocity v If at any instant their mutual distance of separation is x then magnitude of rate of change of capacitance with respect to time varies as 2 27 12 3 x 1 1 R X 4 x X

A 600pF capacitor is charged by a 200V supply It is then disconnected from the supply and is connected to another uncharged 600 pF capacitor How much electrostatic energy is lost in the process

Find the charges on 6 F and 4uF capacitors in the circuit she in figure 2 233 in steady state 3 F HP F5V 6 F ww 3 52 402 www 2 F H 10V 5V 4 F 65