A free ptih-ball of 8 g carries a positive charge of `5xx 10^-8`C. What must be the nature and magntiude of charge that should be given to a second pith-ball fixed 5 cm vertically below the former pith-ball so that the upper pith-ball is stationary?

A pith-ball A of mass 9xx10^-5 kg carries a chargeof +5muc . What must be the magnitude and sign of the charge on a pith-ball B held 2 cm directly above the pith-ball . A such that the pith-ball. A remains stationary?

A positively charged glass rod attracts a suspended pith-ball. Does it imply that te pith-ball is negatively charged?

A 1 mg ball carrying a charge of 2xx10^-8 C hangs from a thread. When a large conducting plate of charge is brought near the ball, the thread makes an angle of 30^@ with the plate. What is the surface charge density of the plate?

The mass to charge ratio (m//e) for a cation is 1.5xx10^(-8) kg//C. What is the mass of this cation?

Two pith-balls each of mass 5xx10^-4 kg are suspended from the same point by silk threads 0.2 m long equal charges are given to the balls, which separate, until the threads enclose an angle of 30^@ , Calculate the charge on each pith-ball.

A particle of mass 9xx10^-5 g is kept over a large horizontal sheet of charge having surface charge density 5x10^-5 C m^-2 What charge should be given to this particle so that if released, it does not fall down?

Two charges 5 xx 10^-8 C and -3 xx 10^-8 C are located 16 cm apart. At what point(s) on the line joining the two charges is the electric potential zero? Take the potential at infinity to be zero.

The distance between two equal balls having unlike charges is 2cm. The radii of the balls are much less than the distance between them. The balls attract each other with a force of 36xx10^(-5) N. After the ball have been connected by a wire and latter has been removed, the balls repel each other with a force of 20. 25xx10^(-5)N. Determine the original charges on the balls

Two identical balls each have a mass of 10 g. What charges should these balls be given so that their interaction eq3ualizes the force of universal gravitation acting between them? The radii of the balls may be ignored in comparison to distance between them.