There are three co-centric conducting spherical shells A, B and C of radii , and respectively and they are charged with charges , and respectively. The potentials of the spheres A, B and C respectively, are: [2026]
(2)
The electrostatic potential in a charged spherical region of radius varies as where and are constants. The total charge in the sphere of unit radius is . The value of is _________.
(Permittivity of vacuum is ) [2026]
− 12
− 8
− 9
− 6
(1)
Electric field in a region is given by where and . If the electric potential at a point (10, 20) is 500 V, then the electric potential at the origin is ________ V. [2026]
1000
0
500
2000
(4)
Three small identical bubbles of water having same charge on each coalesce to form a bigger bubble. Then the ratio of the potentials on one initial bubble and that on the resultant bigger bubble is : [2026]
(4)
Five positive charges each having charge q are placed at the vertices of a pentagon as shown in the figure.The electric potential (V) and the electric field at the center O of the pentagon due to these five positive charges are: [2026]

(2)