There are two concentric spheres of radius a and b respectively. If the space between them is filled with medium of resistivity `rho`, then the resistance of the intergap between the two spheres will be (Assume `bgta`)

Space between tow concentric spheres of radii r_(1) and r_(2) such that r_(1) lt r_(2) is filled with a material of resistivity rho . Find the resistance between inner and outer surface of the material

A metal ball of radius a is surrounded by a thin concentric metal shell of radius b . The space between these electrodes is filled up with a poorly conducting homogenous medium of resistivity rho . Find the resistance of the interelectrode gap. Analyse the obtained solution at b rarr oo .

Two spheres A and B of radius a and b respectively are at the same potential. The ratio of the surface charge density of A to B is

Two concentric conducting spheres of radii R and 2R are crrying charges Q and -2Q , respectively. If the charge on inner sphere is doubled, the potetial differece between the two spheres will

Two spheres of radius a and b respectively are charged and joined by a wire. The ratio of electric field of the spheres is

A copper cylindrical tube has inner radius a and outer radius b. The resistivity is p. The resistance of . the cylinder between the two ends is

The masses of two spheres are 10 kg and 20 kg respectively. If the distance between their centres is 100m, find the magnitude of the gravitational force between them.