[2008EM/HMW-09]

IMSc-IV Physics-IV : Electricity and Magnetism Jan-Apr 2008 MM : 20 Set-IX : Group Activity-IV Gauss Law, Conductors

        [$\oslash$] Briefly discuss the follwoing questions Q[1]-Q[11] from H.C. Vemra.

1. Q[2] in "QUESTIONS FOR SHORT ANSWERS" on page 139
2. Q[5] in "QUESTIONS FOR SHORT ANSWERS" on page 139
3. Q[7] in "QUESTIONS FOR SHORT ANSWERS" on page 139 of
4. Q[1] in "OBJECTIVE -I" on page 139
5. Q[3] in "OBJECTIVE -I" on page 139
6. Q[7] in "OBJECTIVE -I" on page 140
7. Q[1] in "OBJECTIVE -II" on page 140
8. Q[2] in "OBJECTIVE -II" on page 140
9. Q[4] in "OBJECTIVE -II" on page 140
10. Q[5] in "OBJECTIVE -II" on page 140
11. Q[7] in "OBJECTIVE -II" on page 140[$\oslash$] The electric field due to several point charges can be computed using the superposition principle. Discuss if the superposition principle will give correct answer for the electric field for the following arrangements in Q[12]-Q[14].
12. A point charge and a plastic sphere having charge $Q$ distributed uniformly over the surface.
13. A point charge and a solid sphere made of copper carrying a net charge $Q$ over its surface.
14. A point charge and a spherical shell made of copper carrying a net charge $Q$ over its surface.
15. The electric field due to which of the following configurations is {\it every where} equal to the electric field of a solid metallic sphere, of radius $R$, carrying a charge $Q$?
    1. charge $Q$ distributed over volume of sphere of radius $R$.
    2. a plastic spherical shell having the same radius $R$ with charge $Q$ distributed uniformally over the surface.
    3. a conducting spherical shell having the same radius $R$ with charge $Q$ distributed uniformly over the surface.
16. Fig below shows, in cross section, three cylinders, each of uniform charge $Q$. Concentric with each cylinder is a gaussian surface, all three with the same radius. Rank the three cases according to the electric field on the gaussian surfaces greatest first.  
17. A small charged ball lies within the hollow of a metallic spherical shell of radius $R$. Here, for three situations, are the net charges on the ball and the shell, respectively; (1) +4q,0; (2) -6q,+10q; (3)+16q,-12q. Rank the situations according to
    1. the charge on the inner surface of the shell, most positive first.
    2. the charge on the outer surface, most positive first.
    3. the magnitude of the electric field halfway through the shell, greatest first
    4. the magnitude of the electric field at a point $2R$ from the centre of the shell, greatest first.