Question

Question Part
Points
Submissions Used
High-frequency signals are often transmitted along a coaxial cable, such as the one shown in the figure below. For example, the cable TV hookup coming into your home is a coaxial cable. The signal is carried on a wire of radius R1 while the outer conductor of radius R2 is grounded (i.e., at V = 0 V). An insulating material fills the space between them, and an insulating plastic coating goes around the outside.


//img.homeworklib.com/questions/0d575720-4e55-11ea-be99-b9d27e60de64.gif


(a) Find an expression for the capacitance per meter of a coaxial cable. Assume that the insulating material between the cylinders is air. (Use any variable or symbol stated above along with the following as necessary: ?0.)
C/L =??


(b) Evaluate the capacitance per meter of a cable having R1 = 0.35 mm and R2 = 2.5 mm.
pF/m=??

Answer 1

From Gauss's law we have E( ds = 오 E(2께요 AZI (1) We know potential difference V between the two cylinders is v=-feEdr (2) Substitute equation (1) in the equation (2) we get 最1 ) Now the capacitance(c)per meter of the coaxial cable 1S R. In R,

Please edit your values or let me know if require assistance

Evaluate the capacitance per meter of a cable having R1 = 0.50 mm and R2 = 3.0 mm.

Given that R0.50 mm R 3.0 mm Since from the part (a) we got capacitance per meter of a cable is in Substitute the given data in above equation we get 2Tt 8.85x10-12C2 3.0 mm In 0.50 mm 31 pF/m