A very simple way to measure coaxial cable impedance

An Off-Center “Coaxial” Cable

A “coaxial” transmission line has inner conductor of radius a and outer conductor of radius b, but the axes of these two cylinders are offset by a small distance δ ¿ b. Deduce the capacitance and inductance per unit length, and the impedance Z, accurate to order δ/b. The (relative) dielectric constant and permeability of the medium between the two conductors both unity. The relevant frequencies...

A Simple Way to Measure Health Care Outcomes

A Simple Way to Measure Ethanol Sensitivity in Flies

Low doses of ethanol cause flies to become hyperactive, while high doses are sedating. The sensitivity to ethanol-induced sedation of a given fly strain is correlated with that strain s ethanol preference, and therefore sedation is a highly relevant measure to study the genetics of alcohol responses and drinking. We demonstrate a simple way to expose flies to ethanol and measure its intoxicatin...

“Hidden” Momentum in a Coaxial Cable

Calculate the electromagnetic momentum and identify the “hidden” mechanical momentum in a coaxial cable of length L, inner radius a, outer radius b, when a battery of voltage V is connected to one end and a load resistor R0 is connected to the other. The current may be taken as uniformly distributed over the inner conductor, which has resistivity ρ. The outer conductor has negligible resistivit...

A Coaxial Cable Fabry-Perot Interferometer for Sensing Applications

This paper reports a novel coaxial cable Fabry-Perot interferometer for sensing applications. The sensor is fabricated by drilling two holes half-way into a coaxial cable. The device physics was described. The temperature and strain responses of the sensor were tested. The measurement error was calculated and analyzed.