A long straight metal wire of radius r1= 2.20E-2 m is surrounded by a metalic cy
ID: 1807431 • Letter: A
Question
A long straight metal wire of radius r1= 2.20E-2 m is surrounded by a metalic cylindrical shell of inner radius r2= 1.24E-1 m and outter radius r3= 1.91E-1 m. The axes of the wire and the cylindrical shell coincide. The wire carries a charge per unit length 8.50E-6 C/m and the shell carries a charge per unit length -1.70E-5 C/m. a) Find the magnitude of the electrical field at a position p1= 7.20E-2 m? b) Find the magnitude of the electrical field at a position p2= 1.66E-1 m? c) Find the magnitude of the electrical field at a position p3= 2.21E-1 m?Explanation / Answer
The outer shell contribution to the field is 0, since p1 is inside the outer shell. Only the inner shell contributes and this is a straightforward application of Gauss' Law. and when point is outside cylinder can be assumed to be concentrated with the wire From Gauss's Law, the magnitude of the electric field due to an infinite long wire can be figured as: E=?/(2pi*epsilon*r) ? is the charge density