Electric Field and Potential Questions and Answers

6 A uniformly charged dielectric sphere of radius R carries a charge Q distributed throughout its volume Find the potential difference between its surface and a point at a distance R 2 from the center D A Q 8 ER B 16 EOR C 3Q 167 R 3Q 32 ER

Q2 If the voltage across a bulb decreases by 1 then the percentage change in its power output is 1 1 2 4 3 2 4 5 2 1 3 Subtopic Heating Effects of Current 0 4

40 electric field line if in the electric field of a source charge Q The test charge will not follow path of Fixed Source Test charge charge 1 It has zero velocity when released 2 It has non zero velocity along outward radius when released 3 It has non zero velocity along inward radius when released It has a velocity different

iTutor All India Aakash Test Series for NEET 2021 3 Two conducting spheres of radii 2 cm and 4 cm have equal surface charge density The ratio of electric potential on their surfaces is 1 7 1 2 6 7 4 1 2 3 1 4

Diagram shows symmetrically placed rectangular insulators with uniformly charged distributions magnitude Enet is equal At the origin the net field YA of of X O aligned with the negative x axis O aligned with the negative y axis

The work done required to put the four charges together at the corners of a square of side a as shown in the figure is 1 q 4 a 2 6 q 4 2 6 q 4 None of these q q 1 4 a 2 3 q

3 1 2 4 4 1 5 The dielectric strength of air is 5 x 10 V m The maximum charge that can be given to a solid sphere of radius 1 m is charge is distributed uniformly 1 10 mC 2 5 mC 4 9 mc 5 3 g 3 Which of the following configurations of electrostatic mC

A ring of insullating material is situated at one end of a semi infinite long line of charge If is charge per unit length for ring as well as line charge and R is radius of ring Plane of ring is perpendicular to line charge Finc tension in ring

62 Two conducting spheres each given a charge q are kept far apart as shown The amount of charge that crosses the switch s when it is closed is 1 q 3 3 3q 4 q R 9 2R 2 29 3 4 Zero

NT W AB WA AC WAD ev 27 0 V eV 18 0 V OV B 36 0 V the work W in electron volts done by the electric force on an electron that moves from point A to point B Similarly find W AB 45 0 V D 54 0 V 63 0 V 81 0 V AC WAD and W AE Assume the electron starts and stops at rest Enter your answer

27 Two similar very small conducting spheres have charges 40 C and 20 C and are at a certain distance apart Now they are touched and kept at same distance The ratio of initial force to final force between them is 1 8 9 3 1 9 2 8 1 4 7 8

26 Two insulating rods of equal length R one of charge q and other of charge q form a circle of radius R one rod forms one half of the circle The electric field at centre of circle is 1 Zero 2 JE 3 9 2 ER 4 9 4TE 9 ER

4 The electric field lines due to two charges A and B are as shown in the figure The ratio of charges on A and Bis B 1 3 4 3 1 2 5 The dielectric strength of air is 5 x 10 V m The 2 3 4 4 4 1

23 In the given figure a hemispherical object is located in uniform electric field The electric flux through the curved surface is R Radius of the base E 21 DOE

3 20 68 kN C 4 18 88 N C A point charged particle is revolving around a long straight charged wire under influence of electrostatic force If radius of circular path is r then the time period 7 is proportional to 1 MINIL 3 2 r 4 palu

1 Only a 3 Botha and b 2 Only b 4 Neither a nor b Four identical charged particles of charge 1 C 2 C 3 C and 4 C are placed at x 1 m x 2 m x 3 m and x 5 m The electric field intensity at origin is

3 q 880 q 16 0 4 30 Two point charges placed at a distance r in air exert force F on each other For the charges force 4F on each other the distance to exert a 1 2r ne shoul 2 2 4 Ar should be Divisions of

3 20 J 4 1 62 J 2 Consider a small electric dipole of dipole moment p The electrostatic potential due to the dipole at a distance r closer to positive charge on axial line is V and at a distance r on equatorial line is V2 Calculate the value of V V k 1 k 3 Zero gh Work 2 4 2 kp 2 3kp 2 1 40 ATLE

9 A 4 C charge is placed in some gaussian surface such that outward flux is What additional charge is needed to be placed inside the surface such tha there is net inward flux of magnitude 60 1 6 C 3 28 C 2 14 C 4 10 LC

pEcost 20 20 3 Consider a conducting spherical shell of radius R with 33 4d Shell its centre at the origin carrying uniform positive surface charge density The variation of the magnitude of the electric field E r and the electric potential V r with the distance r from the centre is best represented by the graph Here dotted line represents potential curve and bold line represents electric field curve V r V r 3 E r V r E r 2 E r V r E r EADER TEST SERIES JOINT PACKAGE COURSE q fakta fa 1 r me decla te verfa fa 305 8 farga 30 faga fa faga faga fava V r 3 favaganten all B V r pEcos E r V r E r R 2 V r E r V r E r 0999DMD310320004

In the following four situations charged particles are at equal distance from the argin Arrange them according to the magnitude of the net electric field at origin greatest first ii A iii 5q O i ii iii iv B ii i iii iv C i iii ii iv 34 iv O the O

11 A rigid circular loop of radius r and mass m lies in the x y plane on a flat table and has a current i flowing in it At this particular place the earth s magnetic field is B Bxi B k The value of i so that one edge of the loop lifts from the table is a c mg B B mg TrBx b d mg rBz mg Tr BB

A smiling face as shown in figure consists of a ring of radius 6 cm with charge 3 C a second thin wire of charge 4 C and in shape of a circular arc of radius 4 cm subtending an angle of 90 at the center of full circle and small electric dipole of dipole moment 6 x 10 21 Cm is placed as eyes 2 cm from central point Then net electric potential at the center is 1 4 5 104 V 2 9 105 V 3 9 104 V 4 4 5 105 V I 6 cm 4 cm

A non conducting sphere of radius 10 cm has a charge 3 mC distributed uniformly throughout its volume A bullet having charge 3 mC and mass 10g fired from the surface of the sphere along the diameter directly towards its centre Assuming the sphere to be fixed and neglecting any forces other than electrostatic force the minimum velocity of the bullet so that it can emerge from the other side of the sphere is a 3 10 m s b 3 x 10 m s c 9 10 m s d 9 10 m s

A charge q appears on H atom due to movement of electrons towards oxygen Taking the separation between H atom and oxygen atom as r calculate the dipole moment of a hydrogen molecule Given that cos 52 5 0 6

9 UN PL Two charges q and q are plac apart as shown in the figure below B shame Po nhentung Syn Pathol yn Coating na trzissu I Jusb 2 q ME JCB JF Ut A along vector A C along yontou 2009 q noringnib brandsda The electric field at a point P on the perpendicular bisector as shown as B along vector B

7 Two small balls each having equal po charge Q are suspended by two insulating strings at equal length L metre from a hook fixed to a stand The whole set up is taken in a satellite into space where there is no gravity Then the angle 0 between two strings and tension in each string is 1 0 3 kq 1 2 kq L Q Stand L Q 2 kq 21 kq 2

05 Six charges are placed at the corner of a regular hexagon as shown If an electron is placed at its centre O force on it will be Ar 79 3q 29 F 2g E B A zero C along OC 29 29 D C B along OF D none of these

A If a dielectric is inserted to fill the gap between the plates of a capacitor connected to a battery then electric field inside the capacitor decreases R Magnitude of electric field inside a medium is times the potential gradient in that 1 K medium

Find the angular position 0 where the elec tric field due to an electric dipole is perpen dicular to the dipole moment P 0 E A tan 3 C tan 5 B tan 2 D tan 7

The electric field at the surface of a positively charged spherical conductor with surface charge density of C m and a 1 J radius of 1 m decreases by a factor of 2 if x number of electrons are added to its surface The value of x in unit of 10 2 is A 0 125

Solve this Q Find the electric potential at the point O due to segment of ring as shown in figure whose linear charge density is 4 C m y K 1 3 8 10 2 V 2 3 8 10 0 v 3 4 8 10 0 V 4 4 8 10 2 V 60 R 4m

Two charged thin infinite plane sheets of uniform surface charge density and where lo lol intersect at right angle Which of the following best represents the electric field lines for this system A C 0 0 B D 62211 FRR111 0

RESPECTED SIR MAM FOR ME IT SEEMS TO BE SHORT CI RCUITED IN 4 CAPACITORS PLEASE EXPLAIN IT HOW TO C ONSIDER SHORTCIRCUIT IN CAPACITOR AND RESISTOR AL SO 25 Five capacitors are joined in a circuit as shown in the figure The capacitance of each capacitor is 1 4 F The equivalent capacitance between points A and B is GA A B 1 Zero 3 9 F 2 6 F 4 7 uF

to q at th on Example 1 6 Consider three charges 9 92 93 vertices of an equilateral triangle of side 1 What is the force charge Q with the same sign as q placed at the centroid of the triangle as shown in Fig 1 9 3kQq 1 ezt 3k69 22 A 9 9 F E3 1 120 F2 z A

In the given set up the parallel plate capacitor AB has vertical plates with plate separation 50 mm and capacitance C From the plate A a small conducting ball of mass m capacitance C hangs from a non conducting silk thread of length 100 mm The ball initially touches the plate A which is connected to a power supply of voltage V for a short time by closing the switch 5 and then opening it again The plate B is grounded The motion of conducting ball is now observed It is observed that due to the charge deposited on plates and ball the ball swings across touches the plate B returns touches A and finally swings out again such that it almost touches plate B Taking g 10 ms and based on the above facts answer the following questions B 7 The angle made by ball and string with the plate A when the ball is in its final position is A 30 C 60 8 The ball initially touches plate B it loses its charge to B swings back and touches A and then finally again swings out and almost touches plate B The new common potential V is given by B A 4 CV C C B 45 D 0 C V my Covo C C

f inductance of two n a core as shown in inductance of each n is moving in ed v If B I and and R is the ower delivered Last Leap for NEET Par a semicircular conducting loop ACB is rotating with constant angular velocity to about O the which of the following graphs shows the variation induced current with time t The magnetic field is perpendicular to the plane of loop as show in the figure 1 3 3 100 B X X X X xxx XXX X X X X X X xxx X X xXx X X E N p 2 2 he M 2 4 2 nel slotti The circu 2 Dec 3 Fee 4 All The so axis P plane the loc 1 2 3

Figures below show regular hexagons with 19 charges at the vertices In which of the following cases the net electric force at the centre is not zero 1 qd 3 qo q bq 24 09 2 qd 4 go fax at 1 qo 3 qo faff 99 o f fun ga

The wooden beam is constructed from three boards that are fastened together using nails with s spacing along the beam as s For b 12 in h 5 in and 4 14 in determine the area moment of inertia of the cross section about the neutral axis in b N A 1 in

A charged particle having charge q and mass m is projected into a region of uniform electric field of strength with velocity V perpendicular to E Throughout the motion apart from electric force particle also experiences a dissipative force of constant magnitude q E and directed opposite to its velocity If V 6 m s then find its speed when it has turned through an angle of 90 mass m and radius r and the ring is placed on

3 Two copper balls each of mass 6 35g are kept at a separation of 10cm in air If one electron from every 1010 atoms is transferred from one ball to another the force between balls will be atomic weight of copper 63 5amu 1 8 3 10 N 2 4 15 10 N 3 8 3x10 N 4 8 3 102 M

Consider a conductor of variable cross section in which current is flowing from cross section 1 to 2 Then which of the following statement is correct A current passing through both the cross section is the same B Current through 1 is less than that through 2 C Drift velocity of electrons at 1 is less than that at 2 D Drift velocit at both the groce contionn

stration 7 Two charges each of magnitude Q are fixed at 2a distance apart A third charge q of mass m is placed at the mid point of the two charges now q charge is slightly displaced perpendicular to the line joining the charges then find its time period

Two particles are fixed to an x axis particle 1 of charge q1 2 73 x 10 8 C at x 17 0 cm and particle 2 of charge q2 5 29q1 at x 76 0 cm At what coordinate on the x axis is the electric field produced by the particles equal to zero

A disk of radius 4 having a uniformly distributed charge 6 C is placed in the X Y plane with its centre at a 2 0 0 A rod of length a carrying a uniformly distributed charge 8 C is placed on the x 5a a axis from x 4 to x 4 Two point charges 7 C and 3 C are placed at 3a 3a 44 34 0 a a 2 2 0 and respectively Consider a cubical surface formed by six a a surface x 2 y electric flux through this cubical surface is y a 2 z 2 The X

For the magnetic dipole in the figure find the force exerted by first dipole on the second dipole Where m m and m m determine whether the force is repulsive or attractive m2 y

Condition of charging and indicate the direc and electrolyte Q10 Define current density Write it s relation with electric field Q11 Using Krichoff s law determine current through each rocintor

21 Consider the following charged suspended ball 21 system If a B then the statements which can be true at equillibrium out of followings A a Q Q b Q Q c Q Q d Q Q 1 Only d 3 c d m m m m m m m m m m 2 Only c 4 b d faferfera frafa afera e faremo farem fa af at exa a Q Q b Q Q c Q Q d Q Q 1 d 3 c d A m m m m m m m m m m 2 dec 4 b d

A particle A having a charge of 4 x 10 6 C and a mass of 600 g is fixed at the bottom of a smooth inclined plane as shown Another particle B of same mass and charge is placed on incline such that it remains in equilibrium Then dis B 1 2 1 m d 37 2 0 2 m 2

Electric field inside the given capacitor with dielec material is k Find charge density a on the plates Given E 6 10 V m k 6 183 10 C m 3 18x10 G m b 81 10 C m d 3 18 10 C m