How much does a publicist charge?

How much charge is on the outer surface of the conductor?

• A conductor with an inner cavity, like that shown in Fig.22.23c from the textbook, carries a total charge of +4.10nC . The charge within the cavity, insulated from the conductor, is -5.90nC . How much charge is on A)How much charge is on the inner surface of the conductor? B)How much charge is on the outer surface of the conductor?

• Answer:

  If you open your textbook and turn to pg 767 and view figure 22.23c, you can get an idea of how then problem looks. Then turn the page over and look at figure 22.24. Now in your problem, you have a -5.9nC charge in the center, surrounded by a conductor. Draw an imaginary Gaussian surface like that in figure 22.24, creating two layers of the conductor. Now, the charge of this "inside" layer must be equal to 0. Currently the charge is -5.9, so to make it 0 the charge has to be +5.9. There's your first answer. Now you have the figure out the "outer" shell. It tells you that the total charge of the whole conductor is only +4.1nC, yet we have already given a charge of +5.9nC to its "inner" shell. We must give a charge of -1.8 to the "outer" shell, giving the whole conductor a charge of +4.1nC ( +5.9 - 1.8 = 4.1 ). Or, if you just want the answer- A) +5.9nC B) -1.8nC