Coaxial Cable A has twice the length, twice the radius of the inner solid conductor, and twice the radius of the outer cylindrical conducting shell of coaxial Cable B. What is the ratio of the inductance of Cable A to that of Cable B?
C) 2

Question

Quizplus · Accepted Answer

The inductance of a coaxial cable is proportional to the natural logarithm of the ratio of the outer to inner radii. Since cable A has twice the radius of cable B, the ratio of the outer to inner radii for cable A is also twice that of cable B. Therefore, the natural logarithm of the ratio of the outer to inner radii for cable A is twice that of cable B. The inductance of cable A is therefore twice that of cable B. Therefore, the ratio of the inductance of cable A to that of cable B is 2:1. Hence, the correct answer is C.

Coaxial Cable a Has Twice the Length, Twice the Radius