1. A repulsive force of magnitude _________ N is acting between two electrons due to their charges when they are separated 1 cm apart.a) 2.3 x 10-67b) 1.3 x 1067c) 2.3 x 10-24d) 2.1 x 10-242. If substance is made charged by friction __________a) Then protons transfer from one substance to other substanceb) Then new positive charge is generated in it.c) Then electrons transfer from one substance to other substanced) Then new negative charge is generated in it.3.

The repulsive force between two point charges having magnitude + 4 C and +2 C is 8 N. If -4C charge is added to both of them, than the force existing between them is______________ Na) 0b) 8c) 4d) 124. 1019 electrons are removed from the neutral metal plate than the charge remaining on the plate would be _______C a) +1.6b) -1.6c) 10-19d) 10195. q and 9q are placed 60 cm away from each other. At which point on the line joining them the electric filed would be zero?a) 45 cm away from 9qb) 30 cm away from qc) 15 cm away from 9qd) 20 cm away from q6. Two point charges of q and 4q are kept 30 cm apart. At a distance..., on the straight linejoining them, the intensity of electric field is zero.a) 20 cm from 4q b) 7.5 cm from q c) 15 cm from 4q d) 5 cm from q7. A coulombian force between two charged particles at distance r is F. Then at distance it will be F/4.a) 2rb) 3rc) r/2d) r/48. Intensity of an electric field due to infinitely long line distribution of a electric charges is decrease by .a) 1/rb) 1/r2c) r2d) 1/r39. The electric force acting between two point charges kept at a certain distance in vacuum is .If the same two charges are kept at the same distance in a medium of dielectric constant K. The electric force acting between them is.a) b) Kc) K2d) / k 10. .. is the instrument to know weather substance is charged or not.a) Electroscopeb) Electrometerc) Voltmeterd) Ammeter11. The Force acting between two point charges kept at a certain distance is . Now magnitudes of charges are doubled and distance between them is halved, the force acting between them is a) b) 4 c) 8 d) 16 12. An electric dipole is placed in a uniform electric field. The resultant force acting on it a) always be zerob) depends on its relative positionc) never be zerod) depends on its dipole moment13. An electric dipole is placed in an electric field of a point charge, thena) the resultant force acting on the dipole is always zerob) the resultant force acting on the dipole may be zeroc) torque acting on it may be zerod) torque acting on it is always zero.14. When an electron and a proton are both placed in an electric field ..a) the electric forces acting on them are equal in magnitude as well as directionb) only the magnitudes of forces are samec) accelerations produced in them are samed) magnitudes of accelerations produced in them are same.15. The distance between two point charges 4q and q is r. A third charge Q is placed at their midpoint. The resultant force acting on q is zero then Q =.a) qb) qc) -4qd) 4q16. When two spheres having 2Q and Q charge are placed at a certain distance the force acting between them if F. Now they are connected by a conducting wire and again separated from each other. How much force will act between them if the separation now is the same as before, the force acting between them will be _________a) Fb) F/2c) F/4d) F/8