The radii of two insulated metal spheres are 5cm and 10cm. 10 e.s.u. and 15 e.s.u. of charges are respectively given to them. Find the amount of energy lost when the spheres are joined together.

The radii of two insulated metal spheres are 5 cm and 10 cm. They are charged up to potential of 10 esu and 15 esu, respectively. If the two shperes are connected with one another, what will be the loss of energy?

Two insulated metal spheres of the same size are charged with -15 esu and +25 esu. The distance between their centres is 10 cm. What is the force acting between the two charges? If the two spheres are made to touch each other and then placed in their previous positions, what will be the force acting between them?

Two insulated charged spheres of radii 20 cm and 25 cm respectively and having equal charge q are connected by a copper wire and then they are separated

The external and interenal diameter of a hollow metal spheres are 12cm and 10cm respectively. If the density of the metal be 4.9 gm/cc, then find the mass of the hollow sphere.

AB and CD are two perpendicular diameters of a circle of circumference 20pi cm. There are +10 esu, +10 esu, +10 esu and -10 esu of charges at A, B, C and D respectively. What is the Intensity of electric field at the centre O of the circle? What is the direction of the field?

The radii of two concentric circular coils are 8 cm and 10 cm and the number of turns in them are 40 and 10, respectively. A 5A current is passing through each of them In the direction. Determine the magnetic field produced at the centre of the two coils.

Three metallic spheres of radii 6 cm, 8 cm and 10 cm respectively are melted together to form a single solid sphere. Find the radius ofthe resulting sphere.

The radii of two spheres are 10 cm and 40 cm , and their potentials are 40 V and 10 V, respectively. What will be their common potential if they are connected by a conducting wire?

The radius of a charged hollow metal sphere is 5 cm and its surface potential is 10V. Potential at its centre is

The radii of two circles are 10 cm and 5 cm and the distance between their centres is 13 cm. Find the length of the direct common tangent to the two circles.