# Electric Field and Potential Questions and Answers Physics
Electric Field and Potential
1 Two particles carrying charges q and q and having equal masses m each are fixed at the ends of a light rod of length a to form a dipole The rod is clamped at an end and is placed in a uniform electric field E with the axis of the dipole along the electric field The rod is slightly tilted and then released Neglecting gravity find the time period of small oscillations Physics
Electric Field and Potential
A conducting spherical shell is given charge 2Q A point charge Q is kept inside the shell at point O as shown Now if charge Q is shifted from point O to point P then magnitude of electric field at point A outside the shell will 2Q O P Conducting shell 26 2 fr 26 5 26 Action Y W 335 20 1 Increase 2 Decrease 3 Remain constant AY Ipproppo or decrease depending on distance Physics
Electric Field and Potential
20 Three charges Q q and q are placed at the vertices of a right angle triangle isosceles triangle as shown If the net electrostatic potential energy of the configuration is zero value of Qis 1 3 q 2 2 2q 2 2 a q a 9 9 2 2 2 4 2q 2 2 Physics
Electric Field and Potential
equilateral triangle with the ends of the piece 6 A long straight wire carries a current i Let B be the magnetic field at a point P at a distance d from the wire Consider a section of length 1 of this wire such that the point P lies on a perpendicular bisector of the section Let B be the magnetic field at this point due to this section only Find the value of d l so that B differs from B by 1 Physics
Electric Field and Potential
Two free positive charges 4q and q are a distance apart What charge Q is needed to achieve equilibrium for the entire system and where should it be placed from charge q 4 1 Q q negative at 3 4 2 Q q positive at 3 3 Q q positive at 4 Q q negative at 1 3 1 3 Physics
Electric Field and Potential
0 Three concentric metallic shells A B and C of radii a b and c a b c have surface charge densities o o and o respectively i Find the potentials of three shells A B and C ii It is found that no work is required to bring a charge q from shell A to shell C then obtain the relation between the radii a b and c O Physics
Electric Field and Potential
30 Equal charges q are placed at the four corners A B C D of a square of length a The magnitude of the force on the charge at B will be MP PMT 1994 DPMT 2001 1 b a 39 4 4q 2 4 2 q X 1 2 2 1 2 2 d 2 2 24 a Physics
Electric Field and Potential
Answer the following questions in brief A glass rod is rubbed against a silk cloth Which object s gets get charged in this process 1 3 4 5 neither between two opposite charged clouds nor between a charged cloud and the ground 6 Name two objects a that can be charged by rubbing b that do not get charged on rubbing State the main difference between a conductor and an insulator Name the device used for protecting tall buildings from lightning strikes Give the meaning of the term earthing List down two precautions that a person can take if he is caught outside in the open during a lightning strike stions the dod plastic straw that Physics
Electric Field and Potential
ILLUSTRATION 3 51 Figure shows three thin concentric spherical shells A B and C with initial charges on A B and Cas 30 20 and Q respectively The shells A and C are connected by a wire such that it does not touch B Shell B is earthed Determine the final charges 9 9 and a 3 R R 20 30 2 R Q B Physics
Electric Field and Potential
5 placed at vertex A due to the other charges Four charges each of Q Coulomb are situated at the four vertices of square of side length a Find the net force on the charge placed at vert A due to the other charges Physics
Electric Field and Potential
2 Two infinitely long uniformly charged non conducting sheets of charge density o 2 x10 each are placed perpendicular to each other as shown in figure What is the resultant electric field intensity at point P O at Isitms P O 0153 976 rito8 odt noiget al AV Physics
Electric Field and Potential
1 ABC is an equilateral triangle of side 2m If E 10NC then V V is A A 1 10Y 2 10V B 3 20V 4 20V Ya and x 2a If the potential energ Physics
Electric Field and Potential
11 Positive and negative point charges of equal magnitude are kept at 0 0 a 2 and 0 0 a 2 respectively The work done by the electric field when another positive point charge is moved from a 0 0 to a 0 0 Physics
Electric Field and Potential
A short dipole of dipole moment pj is the centre of a spherical cavity inside a solid metal sphere as shown Electric field at point P as shown on the x axis due to charges induced on the surfaces of the metal sphere is of 1 koj 3 2kn V A iO R P X 2 k ng 3 r Physics
Electric Field and Potential
Take g 10 m s Two like charged infinitely long parallel wires with the same linear charge density of 3 10 C cm are 2 cm apart The work done against electrostatic force per unit length to be done in bringing them closer X by 1 cm is 100 J m Find the integer closest to x Corporate Office CG Tower A 46 52 IPIA Near City Mall Jhalawar Road Kota Raj 324005 in IF mail contact resonance ac in ADVES 122 Physics
Electric Field and Potential
2 Two opposite and equal charges 4 108 coulomb when placed 2 102 cm away form a dipole If this dipole is placed in an external electric field 4 x 108 newton coulomb the value of maximum torque and the work done in rotating it through 180 will be a 64 104 Nm and 64 104 J b 32 10 Nm and 32 104 J c 64 104 Nm and 32 104 J d 32 104 Nm and 64 104 J