Question

(0,d) Pod,d)

An infinitely long solid insulating cylinder of radius a = 5.6 cm is positioned with its symmetry axis along the z-axis as shown. The cylinder is uniformly charged with a charge density ρ = 25 μC/m³. Concentric with the cylinder is a cylindrical conducting shell of inner radius b = 14.5 cm, and outer radius c = 17.5 cm. The conducting shell has a linear charge density λ = -0.41μC/m.

1. What is V(P) – V(R), the potential difference between points P and R? Point P is located at (x,y) = (42 cm, 42 cm).

2. What is V(c) - V(a), the potentital difference between the outer surface of the conductor and the outer surface of the insulator?

3. Defining the zero of potential to be along the z-axis (x = y = 0), what is the sign of the potential at the surface of the insulator? V(a) < 0 V(a) = 0 V(a) > 0

4. The charge density of the insulating cylinder is now changed to a new value, ρ’ and it is found that the electric field at point P is now zero. What is the value of ρ’?

Answer 1