Electric field in a wire: A tube of mercury with resistivity 9.84 × 10^-7 Ω ∙ m has an electric field inside the column of mercury of magnitude 23 N/C that is directed along the length of the tube. How much current is flowing through this tube if its diameter is 1.0 mm?

Question

Quizplus · Accepted Answer

The current flowing through the tube is given by:$$I = \frac{E}{ ho} \pi r^2$$where:* E is the electric field strength (23 N/C)* ρ is the resistivity of the mercury (9.84 × 10^-7 Ω ∙ m)* r is the radius of the tube (0.5 mm or 5 × 10^-4 m)Substituting these values into the equation, we get:$$I = \frac{23 ext{ N/C}}{9.84 imes 10^{-7} \Omega \cdot ext{m}} \pi (5 imes 10^{-4} ext{ m})^2 = 18 ext{ A}$$Therefore, the correct answer is A) 18 A.

Electric Field in a Wire: a Tube of Mercury with Resistivity