A coaxial cable consists of an inner metalwire of radius r1 and and outer metal

Question

   A coaxial cable consists of an inner metalwire of radius r1 and and outer metal cylinder of radius r2. There is current I1 to the right in the wire and current I2< I1 to the left in the cylinder. Consider a circular Amperian path of radius R centered on the wire and perpendicuar to the wire. Determine the magnitude and direction ofthe magnetic field at a location R above the wire, far from the ends of the coaxial cable. Explain in detail, including all assumptions, directions, calculations, etc. Don't skip steps.

       A coaxial cable carryingcurrent.

Explanation / Answer

From Amperes law the line integral of a magnetic field B along a closed curve is equal to the ?0 times net current i throught the area bounded by the curve is

                          ? B ds = ?0 i

                          B ( 2?R ) = ?0 i

                          B = ?0i / 2?R

the current flowing through the cyclinder is I2> I1 therefore we get

                 B = ?0 i_2 / 2?R

The current in the cylinder flows in the left direction,therefore the magnetic field at R above the wire is into the plane of the board

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.