Electric Field and Potential Questions and Answers

A charge q is moved from A to Calong the path ABC as shown in figure The work done in moving charge from A to Cis a B 45 A qEa OqEva 6 qEb qEb 5 b 45 C

1 c ab 3 c ab CRA In the circuit shown below C 10 F C C 20 F and C 40 F If the charge on C is 20 uC then potential difference between X and Y is C 2 c a b C C 1 2 V 2 3 V 3 6 V 4 3 5 V The charge in the 2uF capacitor at steady state is 17 18 1 c ab 3 c ab C 40 FC YONGER THI 1 2 V 4 c 6 C 10 F C C 20 F 20 ctaxam 2 c a b 2 3 V HH 3 6 V Y 4 3 5 V

5K 4K 1 1 9 2AE k 4K 3K 1 2 Two charged capacitors have their outer plates fixed and inner plates connected by a spring of force constant k The charge on each capacitor is q Find the extension in the spring at equilibrium www 3 smooth 2 4 Ack 3K 2K 1 2K K 2 Ar k Zero 5K 4K 1 1 Telegram ne question paper 1 2 24 rafer fa fastafe uch I fredien fesin get af qt fein forran m 2A k 4K 3K 1 2 www smooth 3K 2K 1 q 4 Ask 3 2K K 2 Ak 4 T

1 16 2 20 3 4 4 2 15 Positive point charge q is placed at distance 2R from the surface of a metallic shell of radius R The electric field at centre of shell due to induced charge is 2R 1 Zero 3 4 1 9 4R 1 2 41 4 4 1 9R2 q R2 15 1 16 2 20 3 4 4 2 TR N T I T H I THE 2R G H atren 4 xet my l m 9 n qu nH SI d thin ser 1 gaat after O 1 3 41 q 4R 2R q 2 1 9 9R 47 4 4 1 q R

A particle of charge q mass m moves in a circle 7 of radius r around an infinitely long line charge on linear charge density 2 Then time period will be 1 T 2 xr 3 T m 2kAq 1 2nr m 2k q n Teat 2 T 4 T q Telegram ne question and there and q 4x m 2k q m 1 2 r 2k q 1 T 2 r 3 T 1 2nr a fer am m 2kAq 2k q 2 T 4 T q 4x m 2k q 1 m 2 r 2kq 1001CH02021200

ALLEN Figure shows two uniformly charged large non 5 conducting sheets having surface charge densities 20 and respectively A B and C are three points E be the electric field at point B then electric field at point A can be given by e 2E 20 0 1 B 2 C 3 3 2 4 3E fe 1 Ef W 00 3E 20 A fera farge fam 03 tener ufgefor Baga B 2 colm 4 3

2C and 6C two charges are repelling each other 1 with a force of 12N If each charge is given 2C of charge then the value of the force will be 1 125 Attractive 2 4N Repulsive 4 Zero 3 8 N Repulsive 2 6C N V 12 fenf 2C fear and 36 1 125 3 3 8 N a 2 4N uffi 4

2E 1 E 2 3 4 3 An electron enter with velocity 4 x 107 m s in the 6 electric field of 3200 volt meter perpendicular to t and it covers 0 10 meter distance The electron 3E 2 will be deflected by 1 1 76 mm 3 176 mm 2 17 6 mm 4 0 176 mm 3 3 4 3 4 x 10 m s 3200 ter forge 0 10 metre 1 1 76 mm 3 176 mm falfafura 2 17 6 mm 4 0 176 mm

The magnitude of electric field due to a uniform sphere of charge of radius R at distance 2R from its centre is equal to that at distance x from the centre where x 2R The value of x is R 2 3R 4 R4

ALLEN Three concentric metallic shells A B and C of radil a b and c a b c have surface charge densities o o a respectively If the shells A and Care at the same potential then the relation between the radii a b and c is 1 c ab 2 c a b 3 c ab 4 c b In the circuit shown below C 10uF C C 20uF a b c a b c siatif a ba cft 1 c ab 3 c ab fufa A BR c for fram A Cfara fr 2 c a b 4 c b C 10uF C C 20uF F

amplitude 2k 3 not perform SHM but will have a periodic motion 4 remain stationary Electric flux through surface area 100 m lying in xy plane if i 2 3k N C in N m C 1 100 2 141 4 3 173 2 4 200 perform 3 4 femm x 100 m 4 2k crea ufani feE 1 2 3k N C N m C 2 141 4 3 173 2 4 200 1 100

A uniformly charged ring of radius 1 0 m has charge Q 5 0 C The magnitude of electric force exerted by the ring on a point charge of 2 0 C kept on its axis at a distance of 3 m from its centre will be O 45 3x10 N O 90 3x10 N 45 3 x 10 N

Two point charges Q and 20 are fixed on 13 after far the X axis at positions a and 2a from origin respectively At what positions on the axis the sh a de 2a feffer for fearf resultant electric field is zero kun faga 1 Only x 2a 3 Both x tv 2a 2 Only x 2a 3a 4 X only 2 1 de 3 1x 2a 1x 2a 2a 2 andel X 1 3a 4 x andel

Electric field intensity at centre of semicircular 16 gada are as shown in fig is 82 1 10 10R 2 10 22 3 k 4 5 2 OR Telegram an Brit 1 10 2 10 2 k 3 5 R Szk R 4 5 2 82 OR 6

A particle with mass 1 0 mg having charge 2 0 C move under the action of a uniform electric field of 21 31 N C If the velocity of the particle at t 0 is 1 2 m s its velocity at t 2 s will be O 8i 12 m s O 9i 10 m s O 81 12 m s 6i 8j m s

There are two concentric conducting spherical shells of radius R and 2R respectively Inner shell is given charge Q and outer shell is neutral If both shells are connected by conducting wire then heat loss is Only one correct answer A B C Q 8TER 16TER Q 4TEOR

Which of the following is true when a dipole is placed in non uniform and increasing electric field Only one correct answer A Net force on it is always equal to zero B Torque can not be zero C Torque must be zero

The curve represents the distribution of potential along the straight line joining the two charges Q and Q2 separated by a distance r then which is of the following statements are correct A Q A Q B C 4 1 Q Q 1 2 Q is positive in nature 3 A and B are equilibrium points 4 C is a point of unstable equilibrium dhe shi VER

A current carrying loop of radius r carries a current I in clockwise direction It is placed in a uniform magnetic field B such that plane of coil makes an angle 30 with the direction of magnetic field The net torque on the coil will be 3r 1B 2 O r lB O Zero

Three electric charges are arranged on a straight line as shown in the figure Q Q2 R R Select True or False for the following statements If Q is positive Q is negative and Q3 is positive then Q MIGHT feel a net force to the right If Q is negative Q2 is negative and Q3 is positive then Q MUST feel a net force to the right If Q is positive Q is negative and Q3 is negative then Q MUST feel a net force to the right If Q is positive Q2 is negative and Q3 is positive then Q MUST feel a net force to the right Submit Answer Tries 0 6 In the above figure R 1 58 m Q 2 06x10 6 C Q Q and Q3 Q Calculate the total force on Q Enter your response as positive if the force is to the right and negative if the force is to the left

Electric potential is given by MER 36 faya fara fact ar faen ent V 6x 8xy 8y 6yz 4z 2nd V 6x 8xy 8y 6yz 4z Then magnitude of electric force acting on 2C point charge placed on origin will be 1 2 N 2 6 N 3 8 N 4 20 N A current of 3 2 mA is flowing through a 37 Telegram ne a after 1 2 N 3 8 N 2 6 N 4 20 N 3 2 muna safata fr

24 If we have an irregularly shaped conductor as 24 ares fanger f shown and a charge is given to it choose the correct statement 5 P 1 the electric field and electric potential at P is maximum among all points of conductor 2 the electric field at P is maximum and electric potential is same at all points of conductor 3 the electric field and electric potential at P is same at all points of conductor P 1 Aga v ga fava en fait m 2 P fargt fa 3 aga va agafava are un fargent 4 the electric field and electric potentiam nequestionpaper at P is minimum among all points of conductor If an electron moves in the direction of electric 25 afe caga faga in sem f 4 aga agafava affari

A solid sphere of radius R is charged uniformly At 26 what distance from its surface is the electrostatic potential half of the potential at the centre 1 R 2 R2 3 R 3 4 2 R R N HT I NGANH A 3H fe for at for fagd fara fa 1 R 3 R 3 2 R2 4 2 R

If we have an irregularly shaped conductor as 24 shown and a charge is given to it choose the correct statement P afs feandurg an ander fam 1 the electric field and electric potential at P is maximum among all points of conductor 2 the electric field at P is maximum and electric potential is same at all points of conductor 3 the electric field and electric potential at P is same at all points of conductor 4 the electric field and electric potential at P is minimum among all points of conductor If an electron moves in the direction of electric 25 afe and can ia faga in ferm f 2 P 1 aga aga agafava ale fa on m ne questionpape farofa 3 aga a daga faca acest and fargen 4 aga vai agafava ale face

A conducting shell S having charge Q is 18 Q surrounded by an uncharged concentric conducting spherical shell S Let the potential difference between S and S be V If shell S is now given a charge 3Q the new potential difference between the same two shell is 1 V 2 2V 3 4V 4 2V ancar v 3Q fear ang at at ayat m 1 V questionpt 2 2V 3 4V 4 2V

An electric dipole is placed along the x axis at 16 the origin O A point P is at a distance of 20cm from this origin such that OP makes an angle questionpaper with the x axis If the electric field at P makes an angle 8 with the x axis the value of 8 would be e W 2 tan 3 4 tan 1 MS amm 2 3 Im tan 4 tan ergfen ve aya faye ten 20 enfa pfeera

11 a Define electric flux Write its S I unit b Using Gauss s law prove that the electric field at a point due to uniformly charged infinite plane sheet is independent of the distance from it How does this electric field change for a thick sheet of charge

A particle with charge qo and mass m is projected from an infinitely large non conducting thin sheet having charge per unit area o with speed Vo at angle 0 with the plate Neglecting gravity the time after which the particle will strike the plane is O 4 mV sine 090 2 mV sine 090

A uniform sphere of charge of radius 1 0 m and charge per unit volume p 2 0 C m is kept with its centre at the origin A spherical cavity of radius 0 25 m with centre on the x axis at x 0 75 m is created in the cavity The electric field at point 0 75 m 0 2 m 0 m inside the cavity will be O 18 x10 NC 67 i 3 j N C O 9 0 2 N C

An insulated sphere of radius R has a uniform 44 R volume charge density p The electric field at a point P inside the sphere at a distance r from the centre is 1 Rp 380 rp 2 30 3 Zero 4 rp 3E0 P farg pufaga a m e Rp 3E0 rp 300 3 Zero rp 300 Telegram ne question paper r feerd

Point charge q 2 C and q 1 C are kept at 40 points x 0 and x 6 respectively Electrical potential will be zero at points 1 x 2 and x 9 2 x 1 and x 5 3 x 4 and x 12 4 x 2 and x 2 92 q 2 C 3 q 11 x 0 3tx x 6 fa git ut fera faga fava farfafura fara m 1 x 2 3x 9 2 x 13 x 5 3 x 4 3x 12 4 x 2 3tx 2

A uniformly charged ring of radius R has Q Electric field at axis of ring at distance from its centre is 1 2 3 kQ R2 2 KQ 3 3 R 3 kQ 8 3 kQ 16 R Teque 39 1 2 3 kQ R 2 KQ 3 3 R 3 kQ 8 R2 3kQ 16 R2 V fra Q R ga m

Consider a uniform solid sphere of charge Q and radius R What is the electrostatic potential energy stored in the region O r R where r represents distance from centre of the sphere 1 Q 4 R 2 Q 10 R

A few electric field lines for a system of two charges Q and Q fixed at two different points on the x axis are shown in the figure These lines suggest that a Q Q l b Q Q c at a finite distance to the left of Q the electric field is zero d Q Q Q

The figure shows two large closely placed parallel nonconducting sheets with identical positive uniform surface charge densities and a sphere with a uniform positive volume charge density Four points marked as 1 2 3 and 4 are shown in the space in between If E E E3 and E are magnitude of net electric fields at these points respectively then d 1 2 d 3 4 sphere d d 1 E E E E4 2 E E E E

Yourself Two charges 10 C and 10 C are placed 5 mm apart Determine the electric field at a A point P on the axis of the dipole 15 cm away from its centre O on the side of the positive charge b A point Q 15 cm away from O on a line passing through O and normal to the axis c the dipole

An isolated metallic spherical thin shell has given a charge Q as shown The parameter r is the distance to be measured from center of sphere Which of the following statement s is are CORRECT Q R A The energy stored in space R r 2R is B The energy stored in space R r 2R is C Energy stored in space 0 r R 2 is Q 16 OR 32 ER Q 16 OR D If switch S is closed the heat generated in wire is S Q STEOR

A charge q 10 C of mass 2 g fig is free to move when released at a distance a from the fixed charge Q Calculate its speed when it recedes to a distance b Assume a 1 m b 10 m Q 103 C Qaq fixed 90 m s b 2 9 m s 3 900 m s 4 none of these BUE 45

SolveLancer Test A dipole is kept at centre of a spherical metal shell as shown in the diagram What is the force on charg Q placed at a distance of r from the centre of shell a Data insufficient b kqQa 23 c Zero SolveLancer Test

A charged particle q is shot towards another charged particle Q which is fixed with a speed u It approaches Q upto a closest distance r and then returns If q is shot with speed 2u the closest distance of approach would be 3 2r 4 r 0 2 r 2

A closed surface with two parallel bases is completely immersed in a uniform electric field 5 0x10 N C as shown in figure Find the electric flux through the surfaces 1 S 2 S 3 Sa Y cm 2015 105 10 15 20

If linear charge density of a wire of length L 37 af fx ata X depends on distance x from one end as Ap x Find total charge of wire A 1 AL 3 AL 2 AOL L 4 none of these of a thin disc having 38 at an A Xo x L 1 AL 3 AL Rent a SER qrafia 2 AL 4

ALLEI Three charges Q q and q are placed at the 32 vertices of an equilateral triangle of side as shown in the figure If the net electrostatic energy of the system is zero then Q is equal to 1 2 2 q q q

Three concentric spherical shells have r adii a b and c a b e and have surface charge densities and o respectively If V Vn and Vc denote the potentials of the three shells then for c a b We have

Figure shows the electric lines of force emerging 25 from a charged body If the electric field at A and Bare E and E respectively and if the displacement between A and B is r then 1 E E 2 E E 3 EX 4 E Enthusiast Course Il E H 29072020 r Legen Space for Rough Work fax saftra fuus frent arch tya ara rand front mi ti fa Berta 2 EE 3 EA 4 EA r 1001CMD302220005 Page 9 52

Q 51 When electric dipole is placed in uniform electric field its two charges experience equal and opposite forces which cancel each other and hence net force on electric dipole in uniform electric field is zero However these forces are not collinear so they give rise to some torque on the dipole Since net force on electric dipole in uniform electric field is zero so no work is done in moving the electric dipole in uniform electric field However some work is done in rotating the dipole against the torque acting on it An electric dipole consists of two opposite charges each of magnitude 1 0 C separated by a distance of 2 0 cm The dipole is placed in an external field of 105 N C 1 The maximum torque on the dipole is a 0 2 x 10 3 Nm b 1 x 10 3 Nm c 6 10 3 Nm d 4 x 10 3 Nm

P 0 0 d generated due to various charge distributions and the dependence of E on d is found to be different for different charge distributions List l contains different relations between E and d List Il describes different electric charge distributions along with their locations Match the functions in List I with the related charge distributions in List II ut ciru za gch farg P 0 0 d 92 443 fu ld a duz Ea fa f a 3d fazut fg Ma fa 2 1 d qeu f a f a du fra 14 1 1 ah fu mu faa Ma Aya d fazut ww f 1 38 11 f a 3nde faazo y lac I List I E is independent P of d E mc Q Ex R E x S E 8 List II f 11 A point charge Q at the origin Harguz ku ych farg 3aT Q A small dipole with point charges Q at 0 0 1 and Q at 0 0 1 Take 21 d 2 0 0 1 0 0 1 21 d An infinite line charge coincident with the x axis with uniform linear charge 3 density A X ya ygaga Two infinite wires carrying uniform linear charge density parallel to the x axis The one along y 0 z has a charge density I and the one along y 0 z has a charge 4 density 1 Take 2 d z yuma tu fat gy at 313 d az Ma y 0 z det 0 z 3Jf I CH i ch 3d cd 2 d har A P 5 Q3 4 R 1 S 2 Infinite plane charge coincident with the xy plane with uniform surface 5 charge density qat y6893 you de aard Wall G rd 1 4 S 2 B P 5 Q 3 R Correct Answer Your Answer C P 5 Q 3 R 1 2 S 4 D P 4 Q 2 3 R 1 S 5 1

9 Two small metal spheres having equal charge and mass are suspended from some point on the ceiling of a damp room with silk threads of equal length Let center to center distance between sphere be x x 1 1 is length of silk thread Due to ionization of medium charge leaks off from each sphere and they keep on coming closer to each other at a constant rate Let their approach velocity v varies as vox 1 2 If mass of each sphere is m then the rate at which charge varies with dq N 2 mg respect to time is 1x1 Find the value of N 1

10 Two point charges 50 C and 25 C are 20 cm apart as shown The work done to displace 25 C charge from B point to C will be A 50 C 20 cm 1 11 25 J 3 9 29 J 190 Medical 15 cm 25 C B 2 16 45 J 4 3 25 J

3 Charge Q is divided into two parts which are then kept some distance apart The force between them will be maximum if the two parts are a Q 2 each b Q 4 and 3Q 4 c Q 3 and 2Q 3 d e and Q e where e electronic charge