Electric Field and Potential Questions and Answers

The electric field lines distribution due to two charges is shown in the figure Which of the following is correct ru fa ya Rasi a facru f a arifai qui Ay sau ud OPTIONS MARK FOR REVIEW CLEAR SELECTION OA 19Al 198 OB 19A 196 OC 194l 198 D 219Al 19

Q33 A solid spherical conductor has charge Q and radius R It is surrounded by a solid spherical shell with charge Q innerradius 2R and outer radius 3R Which of the following statements is true 2R 3R i The electric potential has a maximum magnitude at C and the electric field hoo a maximum magnitudo at A

A charged oil drop is to be held stationary between two large conducting plates separated by a distance of 25mm If the mass of the drop is 5 x 1015 kg and the charge on it is 10 8 C the potential to be applied between the two plates is g 10 ms density of medium is negligible A 125V B 2500V C 1250V D 450V

If initially flux through hemisphere is zero Now q and q placed according to figure Due to which charge flux through hemisphere will change 9 1 Only 9 2 Only 9 3 Both 4 None 9

A battery does total 100 J of work during charging a capacitor Then final energy stored in the capacitor is ad cura cufea sifa 350f 2 CUIR GINA CRA ya dari 100 J OPTIONS MARK FOR REVIEW CLEAR SELECTION OA 100 J CB 200 J OC 50 J

28 ALLEN 28 Two identical positive charges are placed on the y axis at y a and y a the variation of V potential along the x axis is shown by the graph 1 2 3 4 V X A charged oil drop is suspended in uniform field 29 y a 3 y Es sien 1 2 a fant DIED X 3 x 10 V m ft fad

The external work required to slowly rotate a dipole of dipole moment 1 C m in uniform electric field of magnitude 20 V m from stable equilibrium stat to unstable equilibrium state is 20 V m f ya 1 C m f ya iqui s van faydzien R VRIEND Rufa a diR k gua fay 310246 did R OPTIONS MARK FOR REVIEW CLEAR SELECTION A 40 J OB 40 J C 20 J

ALLEN x ya tabi ani facra a Bi List I gives certain situations in which electric 20 1ff fuf f fa a field is represented by electric lines of forces in x y plane List II gives corresponding representation of equipotential lines in x y plane Match the figures in List I with the figures in List II and indicate your answer 11 x y a fans List I P Q R S Electric lines of forces Electric lines of forces Electric lines of forces Electric lines of forces PQRS 1 1 2 3 4 2 4 321 3 3 4 21 4 21 3 4 1 2 3 Lower potential List II Higher potential Lower potential Higher peal Higher potential Lower potential P Q R S eft I P Q R 1 1 2 4 3 3 4 2 feature Electric lines of forces Electric lines of forces Electric lines of forces Electric lines of forces S 2 3 4 321 421 1 3 4 1 2 3 for Lower potential D Higher potential eft II 3 Higher peal Lower potential Lower petal Higher potential Higher potential Lower potential

17 4 32 0 Series of infinite charges is given then force at 17 3 for at fre charge located at origin will be Y cm luc luc luc 2 4 luc 1 120 N 3 420 N l C 8 00 X cm 2 120 N 4 1806 N 32 0 Y cm l C fed and SPI l C I C I C 4 te BN 1 2 1 120i N 3 420 N 1 C 00 8 X cm 2 120 N 4 180 N

The variation of potential with distance R from a fixed point is as shown in the figure The electric field at R 5m is Potential in volt S43210 HH A 2 5 V m Distance R in m 6 B 2 5 V m C 2 5 V m D 2 5 V m E 3 5 V m

parallel plate capacitive sensor measures displacement In one test the ensor has a time constant of 60 ms in air with standard temperature and ressure When it is subject to a displacement of 100 microns in 80 ms what is i measured displacement If the initial separation between plates is 120 microns what is the ratio of the change in capacitance to initial capacitance at 80 ms

An electric dipole is kept at the origin as shown in the diagram The point A B C are on a circular are with the centre of curvature at the origin If the electric fields at A B and C respectively are E E2 Es then which of the following is incorrect d l 1 El 2 E A E 2E2 ITS 3 E E3 B d C X 24

5 The diagram shows four pairs of large parallel conducting plates The value of electric potential is given for each plate Rank the pairs according to the magnitude of the electric field between the plates least to greatest 20V 70V 1 OA 1 2 3 4 A 1 2 3 4 B 4 3 2 1 C 2 3 1 4 D 2 4 1 3 20V 70V 2 1 poin 10V 90V 11 3 30V 90

Two charges of equal magnitudes and at a distance r exert a force F on each other If the charges are halved and distance between them is doubled then the new force acting on each charge is F 8 c 4F a b d 244K 16

Four identical charge particles each of mass m and charge q are connected through six identical massless and inextensible strings of length l System is kept in a gravity free space Now if string PQ is cut then maximum speed of particle S is 3 1 A C q 8 m q 4 E me 3 1 B D q 8 me q 4 me 1 1 3 1 7 3 3 S 0 P R 70

3 The potential of the electric field at any point x y z is given by V 3x 5 where x y z are in metre and V is in volt The intensity of the electric field at 2 1 0 is 1 17 V mi 3 12V mi 2 17V m7 4 12V mi

Two charges one of which is 1 5 times the other experiences a force of 5 4N when placed at a distance of 10cm On increasing the distance between them by 5 cm the force becomes 2 4N the bigger charge is 1 2uc 2 3 c 3 1 5 c 2 42 514 4 6 c

Column 1 q Q1 x O 02 x 03 3 0 q 04 a 0 90 0 a 10 0 0 a 0 0 0 59 COT 0 0 0 0 a a q a 0 9 a 0 Column ll A1 Increases as x increases in the interval 0 x a A2 Decreases as x increases in the interval 0 sx a A3 Zero at x 0 A4 Decreases as x increases in the interval a x Save Continue

1000 droplets of mercury each of potential 5 volt and radius R combine to form a big drop The potential of big drop is 500 V 50 V 1000 V 100 V

short dipole is placed on the axis of a uniformly charged rin otal charge Q radius R at a distance R 2 from centre of rin s shown in figure Find the force on the dipole due to the ring Q R

If a potential of V x yz Ay z find A so that Laplace equation is satisfied and with the value of A determine electric field at 2 1 1 What are the physical significances of Poisson and Laplace equation

In the figure two point charges 4 0 uC and 2 0 uC are located at opposite corners of a rectangle Determine the electric force Cartesian form and polar form on the charge 2 0uC A 0 400 m 2 00 C 0 800 m 4 00 C B

A uniformly charged solid sphere of radius R has potential Vo measured with respect to on its surface For this sphere the equipotential surface 5V with potentials 3V and 2 have radius R 0 and 4 R2 2 respectively then O R 0 and R R O R 0 and R R OR R and R R

For an isolated charged conductor shown in figure the potential field and charge density at A and B are VA EA OA and VB EB and Og respectively Which one of the following is correct B x x O Only OA OB O Only VA VB O Only EA EB OA OB VA VB and EA EB

V 91 d Here are two charges in a line If q 19 3 nC and d 5 0 meters what is the electric potential at the position of q2 U unit If q2 91 how much potential energy does q2 have at that point 92 unit X W You decide to move q2 so it is only 2 0 meters away from 9 What is the electric potential at that point V unit How much potential energy does q2 have now unit How much work did you have to do in order to move those charges together Unit

An object has a mass of 16 x109 kg and a charge of 580 nC It accelerates from a potential of 0 Volts to 5 Volts How much kinetic energy did it gain How quickly is it now moving unit

If 9 8A are flowing and only 25 8C of charge have gone by then how much time has past Desmos Calculator At unit

Two particles of equal mass 20 mg and equal charge 80 nC are brought from an infinite distance apart until they are only separated by 8 x 10 10 meters The particles are released from rest What speed will they have when they are very far apart from one another Speed m s

A 12 0 Volt car battery can move 56000 Coulombs of charge through a circuit What is its energy output unit

Problem 12 A test charge of 3 C is placed halfway between a charge of 7 Cand another of 5 C separated by 10 cm a What is the magnitude of the force on the test charge b What is the direction of this force away from or toward the 7 C charge

Problem 16 Please Show Work 10 points Show that units of V m and N C for electric field strength are indeed equivalent

3 6 If all 4 switches below are turned on which light bulb will light up W Wood S Silver and Y Yarn A C 1 Circuit C 2 Circuit B 3 Circuit D W B D

The charge in coulombs required to suspend a 3 6x10 12 kg oil drop in an electric field with a magnitude of 1 9x104 N C is 6 9 10 9 C 6 8x10 18 C 5 2 1016 C 5 4 10 14 C 19x10 15 C

Identify the following definitions A continuous flow of electrons Electricity type caused by a build up of electric charge How like charges behave towards one another How unlike charges behave towards one another These materials have lots of free electrons Charge present on an ebonite rod rubbed with fur Method of charging when 2 neutral objects are rubbed together The instrument used to detect if an object is all charged up The other name for charging by contact In induction this accepts electrons or gives up electrons A closed path followed by electrons The amount of charge passing a point in a circuit every second The property of a material that prevents the motion of electrons The rate of using up energy Circuit type in which there is only one path for electrons to follow Circuit type in which there is many paths for electrons to follow Type of circuit in which Is I1 I2 I3 I4 etc Type of circuit in which Vs V V V3 V4 etc The study of static electricity A rapid release of electrons from a charged object The law that explains the relationship between potential difference current and resistance p i j k 1 9 h o m n f e 17 a d b c b c d e f g h i j k 1 m n o p 9 r s

Inner Surface Outer Surface Charge q 1 00 nC Now even though the sphere itself is neutral the charge q inside will cause polarization a separation of charges within an object How much excess charge will be on the outer surface of the shell This is the outermost surface of the system Leave your answer in nC Your answer should include 2 Decimal Places A negative sign if your answer is negative you don t need to use a positive sign for a positive answer that is assumed You can t put in an answer with powers of 10 in this question You ll have to write out the number For Example You can t answer 8 510 x 10

A constant electric field E 100 bounded by the y and z axes and the lines y 40 cm and z 40 cm The electric flux through the plane s surface in N x m C is 0 16 100 is present throughout a region of space that includes the plane none of the other answers is correct 0 16

Ke 4TE 8 99 x 10 2 0 nC The point charge at the bottom of the figure is Q 49 nC and the curve is a circular arc The magnitude of the force on the charge Q due to the other point charges shown is 5 0 cm 3 8 x 104 N 4 5 x 10 N 2 9 10 N 5 4 x 10 4 N 6 0 nC 45 45 1n 10 2 0 nC 5 0 cm

A 20 nC charge is fixed at the origin of a rectangular coordinate frame When a 30 nC charge is placed at point P it experiences an electric potential of 9 0 V due to the 20 nC charge The 30 nC charge is removed and replaced at point P by a 40 nC charge The electric potential experienced by the 40 nC is 18 V 6 8 V 9 0 V O 12 V 4 5 V

15 Base your answer to the following question on the information and diagram below Two small metallic spheres A and B are separated by a distance of 4 0 10 1 meter as shown The charge on each sphere is 1 0 x 106 coulomb Point P is located near the spheres 1 0 10 6 C A A P B 4 0 10 m 1 0 x10 6 C Which arrow best represents the direction of the resultant electric field at point P due to the charges on spheres A and B C B D

Part II Please show work including formula and substitution with units 1 8 5x10 5C 3 1x10 6C 6 4X10 C B 4 2 cm 2 9 cm a Calculate the electric force between A B Pe kaa 1 4 8 99x1071 1 12 8 5 166 3 1 10 042m 6 3706 2 5 6x10 15 N b Calculate the electric force between B pe k49 Y 8 99x16 Nm 12 604x162 3 1X10 6 029m 31 c Calculate the resultant electrostatic force on B 3 5 10 3 1x06 64 106 18x10 9 vect add dir up dk Subtract fiold pattern hetween A B only 4 4 X10 A B 3

A potential difference of 125 mV exists between the inner and outer surfaces of a cell membrane The inner surface is negative relative to the outer surface How much work is required to eject a positive sodium ion Na from the interior of the cell

The figure below shows three small charged beads all lying along the horizontal axis Bead A at left has a 5 75 nC charge Bead B has a 1 40 nC charge and is 3 00 cm to the right of A Bead C has a 2 15 nC charge and is 2 00 cm to the right of B 3 00 cm 18 Select 9c a What is the magnitude in N C of the electric field at a point 2 00 cm to the right of A N C 2 00 cm b A fourth bead with a charge of 5 00 nC is placed at this point What are the magnitude in N and direction of the net electric force on it magnitude N direction n

The figure below shows a uniform electric field of magnitude E 490 N C making an angle of 67 0 with a flat surface of area A 3 60 m What is the magnitude of the electric flux through this surface in N m C HUIL

The figure below shows a small hollow rubber ball hanging vertically from a thin lightweight string The ball has a mass of 7 00 g and a uniformly distributed charge of q 30 2 nC Directly below it is a second ball with the same mass but a charge of q2 58 0 nC Assume this second ball is fixed in place The centers of the two rubber balls are a distance d 2 00 cm apart 91 92 a What is the tension in N in the string N b The string will break if the tension in it exceeds 0 180 N What is the smallest possible value of d in cm before the string breaks cm

The dome of a Van de Graaff generator receives a charge of 5 4 x 10 4 C Find the strength of the electric field in the following situations Hint Review properties of conductors in electrostatic equilibrium Also use the points on the surface are outside a spherically symmetric charge distribution the total charge may be considered to be located at the center of the sphere a inside the dome N C b at the surface of the dome assuming it has a radius of 3 0 m N C c 4 8 m from the center of the dome N C

In the classical model of a hydrogen atom an electron orbits a proton with a kinetic energy of 13 6 eV and an electric potential ene HINT a Use the kinetic energy to calculate the classical orbital speed in m s m s b Use the electric potential energy to calculate the classical orbital radius in m m

The figure below shows three small charged spheres at the corners of an equilateral triangle Sphere A has a charge of 1 85 PC 5 40 C and C has a charge of 5 12 C Each side of the triangle is 0 500 m long What are the magnitude and direction of the net electric force A Enter the magnitude in N and the direction in degrees below the x axis magnitude direction A B 60 0 0 500 m N o below the x axis

7 Two electrically neutral metal spheres 4 and B on insulating stands are placed in contact with each other A negatively charged rod is brought near but does not touch the spheres as shown in the diagram below Negatively charged rod Insulating stands How are the spheres now charged A is positive and B is positive B A is positive and B is negative

charge and position of three metal spheres X Y and Zon insulating stands 4 106 C X OC Y A 1 10 6 C B 2 x 10 6 C OC N 4 Sphere X is brought into contact with sphere Y and then removed Then sphere Y is brought into contact with sphere Z and removed What is the charge on sphere Z after this procedure is completed C 3 106 C D 4 10 6 C

8 Examine the charge distribution shown 9 4 0 x 10 C 92 4 0 x 10 C 4 0 m 3 0 m a What will the net force be on the third charge of q3 3 0 x 10 5 C placed at the point P T I 4 P b What will the total electric potential energy be if the third charge of q3 3 0 x 10 C is placed at the point P T I 4