Two identical copper spheres are separated by 1m in vacuum.How many electrons would have to be removed from one sphere and added to the other so that they now attract each other with a force of 0.9N ?

How many electrons would have to be removed from a copper penny to leave it with a positive charge of 10^(-7) C ?

Twosmall neutral conducting spheres are taken and their centres are separated by a distance 2a. If n electrons are removed from one of them and deposited on the other, what is the magnitude of electric intensity due to the system at a point on the line joining the centres of the spheres and at a distance d from the midpoint of the line joining the two spheres? (e is quantum of charge)

How many electrons must be added to one plate and removed from the other so as to store 25.0 J of energy in a 5.0 nF parallel plate capacitor?

Two identical spherical masses are kept at some distance. Potential energy when a mass m is taken from the surface of one sphere to the other

(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 ?

Two identical conducting spheres 1 and 2 carry equal amounts of charge and are ficed apart at a certain distance larger than their diameters. The spheres repel each other with an electrical force of 88mN. A thired identical sphere 3, having an insulating handle and initially uncharged, is touched first to sphere 1 and then to sphere 2 and finally removed. Find the force between spheres 1 and 2 as shown if Figure. ,

Two small objects are rubbed against each other using insulating handles and then kept at a separation of 1 m from each other in vacuum. Both objects were found to attract each other with a force of 10 N. Assume that the force between the objects is of electrical nature. Calculate the number of electrons that were transferred from one object to another during the rubbing process.

(a) Two identical spheres having positive charges are placed 3 m apart repel each other with a force 8 xx 10^(-3) N . Now charges are connected by a metallic wire, they begin to repel each other with a force of 9 xx 10^(-3) N . Find initial charges on the spheres. (b) Two identical spheres having charges of opposite sign are placed 3 m apart attract other with a force 2.4 xx 10^(-3) N . Now spheres are touched and then placed at original separation repel with a force 10^(-3) N . Find initial charges on the spheres.

Force between two identical spheres charged with same charge is F. If 50% charge of one sphere is transferred to the other sphere then the new force will be :-