Two small spheres each of mass 10mg are , suspended from a point by threads 0.5m long.They are equally charged and repel each other , to a distance of 0.20m .The charge on each of the sphere is `(a)/(21)times10^(-8)C` .The value of 'a' will be
(Given `g=10ms^(-2)` )

Two small metallic spheres each of mass 'm' are suspended together with strings of length 'l' and placed together. When a quantum of charge 'q' is transferred to each the strings make and angle of 90^(@) with each other. The value of 'q' is

Two point charges +2C and +6C repel each other with a force of 12N. If a charge q is given the each of the these charges then they attract with 4N. Then value q is

Two point charge +2 C and +6 C repel each other with a force of 12 N . If a charge of -4 C is given to each other of these charges , the force will now be

Two small spheres, each of mass 0.1 gm and carrying same charge 10^(-9) C are suspended by threads of equal length from the same point. If the distance between the centres of the sphere is 3 cm, then find out the angle made by the thread with the vertical. (g=10 m//s^(2)) & tan^(-1) (1/100) =0.6^(º)

Two positive charges separated by a distance 2m repel each other with a force of 0.36N. If the combined charge is 26muC , the charges are

A sphere of mass 50 gm is suspended by a string in an electric field of intensity 5NC^(-1) acting vertically upward. If the tension in the string is 520 millinewton, the charge on the sphere is (g = 10ms^(-2))

Two small spheres, each having a mass of 20 g, are suspended form a common point by two insulating strings of length 40 cm each. The spheres are identically charged and the speration between the balls at equilibrium is found to be 4 cm . Find the charge on each sphere.

A hollow sphere of radius 0.1 m has a charge of 5 xx10^(-8) C . The potential at a distance of 5 cm from the centre of the sphere is (1/(4pi epsi_(0))=9xx10^(9) Nm^(2) C^(-2))

A sphere of mass 50gm is suspended by a string in an electric field of intensity 5NC^(-1) acting vertically upward. If the tension in the string is 520 milli newton, the charge on the sphere is (g = 10 ms^(-2))

Two identical spheres each of mass M and Radius R are separated by a distance 10R. The gravitational force on mass m placed at the midpoint of the line joining the centres of the spheres is