Potentiometers consist of a resistive element, a sliding contact ( wiper ) that moves along the element, making good electrical contact with one part of it, electrical terminals at each end of the element, a mechanism that moves the wiper from one end to the other, and a housing containing the element and wiper.
32.
Again, the results of investigations were favourable : trials showed that even a thin steel wire, much thinner than that used to tether the static barrage balloons, when drawn in sliding contact across two or more phases, could cause an arc as long as and that arc would be maintained until the circuit breaker opened.
33.
The electrical conductivity of silver is 106 % of that of annealed copper on the IACS scale, and the electrical resistivity of silver = 15.9 n? " m at 20 �C . The high cost of silver combined with its low tensile strength limits its use to special applications, such as joint plating and sliding contact surfaces, and plating for the conductors in high-quality coaxial cables used at frequencies above 30 MHz
34.
It contains ( i ) a detailed study of phenomenological interface constitutive laws ( ii ) a constitutive interface law incorporating the normal deformability of the interface and the Coulomb friction law, ( iii ) formulations of the dynamic and steady sliding contact problems together with proofs on existence and uniqueness of solutions, ( iv ) numerical techniques and algorithms for the study of the dynamic and steady sliding problems, ( v ) numerical finite element results and parametric studies on the stability of steady sliding and on friction induced oscillations.
