If the force between two charged objects at a separation d is to be left unchanged even though the charge on one of the objects is halved keeping the other same, the original distance of separation should be changed to
2d
B d/2
C d/1.414
D d

The force between two charges separated by a distance 1m is 1.8N. The charges are in the ratio 1: 2 then the charges are

In a Young’s double slit experiment, the separation of the two slits is doubled. To keep the same spacing of fringes, the distance D of the screen from the slits should be made

The force between two point electric charges kept at a distance d apart in air is F. If these charges are kept at the sme distance in water, the force between the charges is F'. The ratio F'//F is equal to ……….. .

Two charges spheres are separated at a distance d exert a force F on each other, if charges are doubled and distance between them is doubled then the force is

The plate separation in a parallel plate condenser and plate area is A. If it is charged to V volt battery is diconnected then the work done increasing the plate separation to 2d will be

Two point charges separated by a distance d repel each other with a force of 9N. If the separation between them becomes 3d, the force of repulsion will be

Two charge spheres separated at a distance d exert a force F on each other. If they are immersed in a liquid of dielectric constant K=2, then the force (if all conditions are same) is

Two charge spheres separated at a distance d exert a force F on each other. If they are immersed in a liquid of dielectric constant K=2, then the force (if all conditions are same) is

(a) Two protons are placed at some separation in vacuum. Find the ratio of electric and gravitational force acting between them. (b) Two point charges are placed at separation 3 m in vacuum. What can be the minimum force between them. (c ) A charge Q is to be divided on two objects. What should be the value of the charges in the objects so that the force between them is maximum ? (d) Two insulating small spheres are rubbed against each other and placed 1.6 cm apart. If they attract each other with a force of 0.9 N , how many electrons were transferred from one sphere to the other during rubbing ?

Gravitational force between two masses at a distance 'd' apart is 6N. If these masses are taken to moon and kept at same separation, then the force between them will become :