Question

5.11 A metal micro electrode has a tip that can be modeled as being cylindrical.The metal itself is 1 um in diameter, and the tip region is 3 mm long.

The metal has a resistivity of 1.2 x 10- N.cm and is coated over its circumference with an insulation material 0.2 um thick. The insulation material has a relative dielectric constant of 1.67. Only the base of the cylinder is free of insulation. a. What is the resistance associated with the tip of this microelectode? b. What is the area of the surface of the electrode that contacts the electrolytic solution within the cell? The resistance associated with the electrode-electrolyte interface of this material is 103 0 for 1 cm?. What is the resistance due to this micro electrode's contact with the electrolyte? c. What is the capacitance associated with the tip of the microelectrode when the capacitance at the interface of the electrode-electrolytic solution are neglected? d. Draw an approximate equivalent circuit for the tip portion of this microelectrode. e. At what frequencies do you expect to see distortions when the electrode is connected to an amplifier having a purely resistive input impedance of 10 MO? You may assume that the reference electrode has an impedance low enough so that it will not enter into the answer to this question. If the amplifier's input impedance is raised to 100 MN, how does this affect the

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