The Plasma Globe's Electric Field · AI Generator #GEN-3ED9F9E7

Physics · electromagnetism

Problem

A plasma globe consists of a central spherical electrode of radius R=3.0  cmR = 3.0\;\text{cm} surrounded by a thin spherical glass shell of radius 2R2R. The space between the electrode and glass is filled with low-pressure neon gas. When operating, the central electrode is maintained at a high voltage V0=12  kVV_0 = 12\;\text{kV} while the outer glass shell is grounded. Due to the ionization of the neon gas, the region between the electrode and glass becomes a conducting plasma with conductivity σ=2.5×10−4  S/m\sigma = 2.5 \times 10^{-4}\;\text{S/m}. In steady state, current flows radially outward from the central electrode through the plasma to the grounded glass shell. (a) Find the steady-state current II flowing through the plasma. (b) At what radius rr (measured from the center) is the electric field strength exactly half of its value at the surface of the central electrode? (c) A small dust particle with charge q=−2.0×10−12  Cq = -2.0 \times 10^{-12}\;\text{C} is placed at radius r=4.5  cmr = 4.5\;\text{cm}. What is the magnitude of the electric force on this particle?

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