THE CONICAL RESISTOR CONUNDRUM - A POTENTIAL SOLUTION

A truncated cone, made of material of uniform resistivity, is given in many introductory physics texts as a nontrivial problem in the comput ation of resistance. The intended method and answer are incorrect and the problem cannot be solved by elementary means. In this paper, we (i ) discuss the physics of current flow in a nonconstant cross-section c onductor, (ii) examine the flaws in the ''standard'' solution for the truncated cone, (iii) present a computed resistance found from a numer ically generated solution for the electrical potential in the truncate d cone, and (iv) consider whether any problem exists to which the stan dard solution applies. (C) 1996 American Association of Physics Teache rs.