(a) The electric field just above the surface of the charged drum of a photocopying machine has a magnitude E of 3.00×105 N/C. What is the surface charge density of the drum, assuming that the drum is a conductor?
(b) The drum of the photocopying machine in the problem above has a length of 48 cm and a diameter of 9 cm. What is the total charge on the drum?
(c) The manufacturer wishes to produce a desktop version of the machine. This requires reducing the size of the drum to a length of 29 cm and a diameter of 7 cm. The electric field at the drum surface must remain unchanged. What must be the charge on this new drum?