Electric Field and Potential Questions and Answers

5 Three identical thin uniformly charged filaments are fixed along three sides of a cube as shown in the figure Length of each filament is e and line charge density on each of them is Determine lectric field at the center of the cube The cube is a geometrical construct and not made of any matter

The supply voltage to a room is 120 V The resistance of the lead wires is 6 2 A 60 W bulb is already switched on What is the decrease of voltage across the bulb when a 240 W heater is switched on in parallel to the bulb JEE Main 2013 2 2 9 volt 4 10 04 volt 1 Zero 3 13 3 volt wer 8 Pusa Road New Delhi 110005 Ph 011 47623456

B In Fig 2 102 three negative charges each amount q and three positive charges q q and Q are placed alternately on the vertices of a regular hexagon If the electric field intensity at O due to the charges at A B C D E is double that at O due to the charge Q what will be the value of Q A 2 R 2 C 2 F Q 2 E D 2 Fig 2 103 9

Two particle x and y having equal charges are accelerated through potential differences V and 4v respectively and enter in a region of uniform magnetic field The particles describe path of radii R and R respectively What is the ratio of masses of x and y

16 An ideal gas is trapped between two metallic pistons A and B inside a thin glass tube The pistons are connected with the terminals of a variable voltage battery Relative permittivity of the gas is The pistons stay in equilibrium at separation xo between them when battery voltage is Vo a Is the equilibrium stable unstable or neutral b How will the distance x between the pistons change if battery voltage is slowly increased

wo point charges charge 2q at x 3R y 0 z 0 and 2q at x 3R y 0 z 0 are placed outside grounded conducting sphere that is centered at the origin a Find expressions for the electric field and the potential in all regions of space b Find the induced surface charge density on the surface of the sphere Identify any regions of zero charge on the sphere and find the locations of with the highest charge densities

n identical cells each of emf E and internal resistance r are joined in series to form a closed circuit One of the cell A is joined with reversed polarity The potential difference across each cell except A is 1 28 n n 2 3 E n 4 1 n E 2n n 2

in this question if a positive charge is shifted from a l ow potential to a high potential the electric potential energy increases acc to the ans why do esn t it decrease because the positi ve charge is moving towards the posi tive charge towards higher potential doesnt there will be any repulsion plz oxplain this teacher

3 TER Two point charges A and B having charges Q respectively are placed at certain distance apart and force acting between them is F If 25 charge of A is transferred to B then force between the charges becomes NEET 2019 1 F 16F 2 9F 16 4F 3 10005 Ph 011 47623456 4

9 3 530 Hz 4 550 Hz If m represents mass v represents velocity and P represents pressure then the dimensional formula mv of in the equation P sin 2 LT 4 ML 1 L 3 ML T is the electrostatic potential The electric field at a point in the region is 10 30 20 10 V 30 30 2 10 V3 10 V 30 cm

ZUIU VICINO selected Negative Marks selected UITIOTIC VI the option 1 If wrong option is There is a uniform positively charged solid sphere having a spherical cavity as shown Consider the points A B C C lying on a line as shown here C is the centre of sphere and C is centre of cavity At which point particle has minimum electrostatic potential B

A solid conducting sphere has cavity as shown in figure A charge q is situated away from the centre A charge q is situated outside the sphere then true statement is 4 4 C A Charge distribution on outer surface of sphere is uniform B Charge distribution on inner surface of sphere is uniform kq q C Magnitude of force on charge q due to induced charge on inner surface of sphere is R 2 l D Magnitude of force on charge q due to induced charge on inner surface of sphere is kq 92 0

4 may be a hyperbola 3 A proton of mass m charge e is released from rest in a uniform electric field of strength E The time taken by it to travel a distance d in the field is 2de 2 2dm 3 2dE 4 2 Ee

Akshay 2 July S pdf he point p is on D Axial Line of P colo EA S 2 Equitorial Line of P sing 1 P coso 1 HITEO d Tan Tan

0 A spherical conductor of radius 10 cm has a charge of 3 2 x 10 7 C distributed uniformly What is the magnitude of electric field at a point 15 cm from the centre of the sphere 1 9x10 Nm C 4x EO 1 1 28 x 107 N C 2 1 28 x 10 N C 3 1 28 x 105 N C 4 1 28 x 10 N C

A particle of mass 10 kg and charge 1 0 C is initially at rest At time t 0 the particle comes under the influence of an electric field t Eosin coti where Eo 1 0 N C 1 and 10 rad s Consider the effect of only the electrical force on the particle Then the maximum speed in ms attained by the particle at subsequent time is

36 The electric field at a point is a always continuous b continuous if there is no charge at that po c discontinuous if there is a charge at that po d both b and c are correct

Consider a metal sphere of radius R that is cut in two parts along a plane whose minimum distance from the sphere s centre is h Sphere is uniformly charged by a total electric charge Q The minimum forcenecessary to hold the two parts of the sphere together is A C Q R h An e R Q R h 32x R B D Q 4xe R Q R h 32x R R

An proton move in a circle of radius 7 10 cm in a 0 666 T magnetic field a What is magnitude and direction show of electron s speed b What are the magnitude and direction show of the resulting force c What is the cyclotron frequency d What value of electric field could make their paths straight

Two thin concentric shells of radii r 1 and r 2 r2 r 1 have charges q 1 and q2 Write the expression for the potential at the surface of inner and outer sphere 150

Suppose the Coulomb s law is defined as F12 statements will be correct K9192 721 F12 3 Then which of the following A Gauss theorem is still valid B The electric potential increases with distance from a positive charge C Like charge would repel D Like charge would attract

ALLEN METU 22 In a certain region of space with volume 0 2 m the electric potential is found to be 5 V throughout The magnitude of electric field in this region is 1 5 N C 2 Zero 3 0 5 N C 4 1 N C

Two short dipoles p i k 4pk ar located at 0 0 0 1 m 0 2 m respectively The resultant electric field du to the two dipoles at the point 1 m 0 0 is A P TEO P C nEO B D P 2 Eo 2p EO

wire rged wire If it is released find its speed when it is at a Show that for a given dipole V E cannot have the same magnitude at distances less than 2 m from the dipole Suppose that the distance is 5 m determine the directions along which V E are equ in magnitude

Two identical copper spheres carrying charges Q and 9Q seperated by a cert ain distance has attractive force F if th e spheres are allowed to touch each ot her and moved to distance of seperatio n x so that the force between them be comes 4F 9 then x is equal to

5 Four equipotential curves in an electric field are shown in the figure A B C are three points in the field If electric intensity at A B C are E EB Ec then C 1 E E Ec B A 2 EA E E

Three identical particles each of charge q are placed at the corners of an equilateral triangle of side L Then the magnitude and nature of the charge at the centre that will keep the system in equilibrium is O 39 39 k

capacitor remains connected to the battery 10 Draw the equipotential surface due to i a dipole ii uniform electric field an iii three equipotential surfaces corresponding to a field that increases in magnitude but remains constant along the z direction 11 State the principle of a copggitor

Example 65 You are given a charge Q at the origin O Refer to Fig 1 90 Consider a sphere S with centre 2 0 0 of radius 2 m Consider another sphere of radius 2 m centered at the origin Consider the spherical caps 1 PSQ ii PRQ iii PWQ with normals outward to the respective spheres and iv the flat circle PTQ with normal along the x axis a What is the sign of electric flux through each of the surfaces i iv b What is the relation between the magnitudes of fluxes through surfaces i iv c Calculate the flux through the surface ii directly Fig Assume that the area of the cap ii is A NCERT Fig 1 90 y 1m S O 0 0 0 P TR 2 0 0 W 94 a encl get Exam

A positively charged ball hangs from a long silk thread Electric field at a certain point at the same horizontal level of ball due to the ball is E If now put a positive test F charge qo at this point and measures then E 90 A B C F L 90 F 90 F 90 Correct Answer My Answer

An infinitely long line of linear charge density is shown in the figure The potential difference VA VB between the two points A and B is A X 2TEO In 2 2r B A Correct Answer

A Proton and an electron are released from an infinite distance apart they get attracted towards Each Other Which of the following statement about their Kinetic energy is true A B C D Kinetic energy of electron is protons Correct Answer Kinetic energy of electron is less than that of Proton Kinetic energy of electron kin proton My Answer None of the above is true as it depends on the distance between the particles

Find out work done by electric field in shifting a point 4 2 charge 27 uc from point A to B which are shown in the figure P dipole moment of given dipole B 1 2 Question Type Single Correct Type 3 2cm 100 3 J 200 3 J 1cm 100 J P 2 10 C m

A charge 9 3 12 C is at a distance d 1 73 m from a second charge q 5 17 C 42 91 a Find the electric potential at a point A between the two charges that is 3d 4 from q Note that the location A in th diagram above is not to scale b Find a point between the two charges on the horizontal line where the electric potential is zero Enter your answe measured from q m

Question 22 At any point x 0 0 the electric potential V is 1000 1500 500 volt then electric field X intensity at x 1 mis B C A5500 1 3 Vm 5500 V m D x2x3 M M 4 00 5500 2 5500 2 N M 1 00 k Vm 1 k Vm Correct Answer My Answer

Two equally charged small metal balls placed at a fixed distance experience a force F A similar uncharged metal ball after touching one of them is placed at the middle point between the two balls The force experienced by this ball is A B F 2 LL F Correct Answer

Two positively charged conductors are put in contact The final value of which of the following quantities of both the conductors will be less than the initial value of one of the conductors O potential O charge Onone of the above 1 pol

ce d ming 1 2 3 1 kq 4 2 d kq 4 2 2d dule Physics arges are arranged at the corners of a square ABCD of side d as shown in Fig Find the work required to put together this arrangement 8kqqo d 4kqq d 9 4kqqo d kq 4 2 3 2d In above question a charge q is brought to the centre E of the square the four charges being held fixed at its cor ners How much extra work is needed to do this E kq 4 2 d 2 4 2 3 11 Find 1

A few electric field lines for a system of two charges Q1 and Q2 fixed at two different points on the x axis are shown in the figure These lines suggest that 1 Point Magnitude of charge Q1 is greater than Q2 Magnitude of charge Q2 is greater than Q1 at a finite distance to the left of Q1 the electric field is zero Q Q1 is negative but Q2 is positive

A conducting shell having charge 15 mC and radius a is surrounded by another concentric conducting shell of charge 15 mC and inner radius 2a and outer radius 3a as shown in the Figure If the inner shell is grounded then C center of she 3a Q 15mC 2a the charge on mer shell o 6 mC the charge on outer surface of outer shell is zero Q

nts are given one labelled Assertion A and the other labelled Reason R Select the correct answer to these questions from the options given below Assertion A Two parallel wires carrying current in same direction attract each other while if two similar charge moving parallel to each other repel each other Reason R Electric force is stronger than magnetic force 1 Point Both A and R are true and R is the correct explanation of A Both A and R are true but R is NOT the correct explanation of A A is true but R is false A is false and R is also false

Question A metallic shell having inner radius R1and outer radii R2 has a point charge Q kept inside cavity Electric field in the region R1 r R2 where r is the distance from the center is given by 1 Point depends on the value of r Zero Constant and nonzero everywhere

Question A hollow metal sphere of radius 5 cm is charged such that the potential on its surface is 10 V The potential at the center of the sphere is 1 Point zero 10 V same as at a point 5 cm away from the surface outside the sphere same as at a point 25 cm away from the surface outside the sphere

Question In bringing an electron towards another electron the electrostatic potential energy of the system 1 Point becomes zero increases decreases Remain same

A particle of mass m and charge q is released from rest in a uniform electric field If there is no other force on the particle the dependence of its speed v on the distance x travelled by it is correctly given by graphs are schematic and not drawn to scale KK 2 1 3

Two small identical electric dipoles AB and CD each of dipole moment p are kept at an angle of 120 as shown in the figure What is the resultant dipole moment of this combination If this system is subjected to electric field E directed along x direction what will be the magnitude and direction of torque acting on this Y qoA X D 9 qB 120 C q X

Two identical spheres A and B carry charge q and q respectively separated by distance r Another identical sphere C carrying charge 5q is first touched with A and then with B and eventually removed Find the new force between A and B spheres

A E 0 B E 0 0 V 0 D V 0 In x y coordinate system a particle P of charge q and mass m enters first quadrant close to x 0 as shown in figure In this region potential varies as V ax Which of the following graphs representing the variation of particle s velocity and acceleration A KKKK C B D

a Draw a plot showing the variation of i electric field E and ii electric potential V with the distance r due to a point charge Q b Two conducting sphere of radii R and R respectively are charged and joined by a thin long wire Find the ratio of Electric field on the surface of spheres

6 Electrostatic shielding Consider a conductor with a cavity with no charges inside the cavity remarkable result is that the electric field inside the cavity is zero whatever be the size and shape of the cavity and whatever be the charge on the conductor and the external fields in which it might be placed We have proved a simple case of this result already the electric field inside a charged spherical shell is zero The proof of the result for the shell makes use of the spherical symmetry of the shell see Chapter 1 But the vanishing of electric field in the charge free cavity of a conductor is as mentioned above a very general result A related result is that even if the conductor Example 4 Strategy Mo p p 380 380 Net field E E E 1 In a uniform sphere of charge charge density p a small cavity is created The centre of cavity is at a distance a from the centre of sphere Taking centre of sphere as origin and as a unit vector along the line joining the centre of cavity and origin show that the electric field at any point inside the cavity is 300 Consider any point Pinside cavity The position vector of P is F The field at P can be assumed to be a superposition of field due to a uniform sphere of charge E and field due to a negative charged sphere of the size of cavity E P F 380 where position vector of Pw r t C pa pa 380 380 C a a you all Fields Since the field at point P does not depend on the position of point P in the ca