A point like charge of +20nC sits at the center of a thick spherical shell of inner radius 4cm and the outer radius 6cm. The shell is made of copper and has a net charge of -10nC.
a) Describe the distribution of charge on the conductor. Sketch some electric field lines, inside and outside the shell.
b) Calculate the magnitude and show the direction of the electric field at 2cm , 5 cm and 8cm from the center.