A solid insulating sphere of radius a carries a net positive charge `3Q`, uniformly distributed throughout its volume. Concentric with this sphere is a conducting spherical shell with inner radius b and outer radius c and having a net charge -Q, as shown in figure

a. Consider a spherical Gaussian surface of radius rgtc, the net charge enclosed by this surface is .............
b. The direction of the electric field rgtc is .............
c. The electric field at rgtc is ............... .
d. The electric field in the region with radius r, which cgtrgtb, is ...............
e. Consider a spherical Gaussian surface of radius r, where `cgtrgtb`, the net charge enclosed by this surface is ................ .
f. Consider a spherical Gaussian surface of radius r, where`bgtrgta`, the net charge enclosed by this surface is ................. .
g. The electric field in the region `bgtrgta` is ................ .
h. Consider a spherical Gaussian surface of radius `rlta`. Find an expression for the net charge Q(r) enclosed by this surface as a function of r. Note that the charge inside the surface is less than 3Q.
i. The electric field in the region `rlta` is ................. .
j. The charge on the inner surface of the conducting shell is .......... .
k. The charge on the outer surface of the conducting shell is .............. .
l. Make a plot of the magnitude of the electric field versus r.