can u help me? tnx An oceanographer is studying how the ion concentrationin sea water depends on depth. She does this by loweringinto the water a pair of concentric metallic cylinders(Fig. P27.68) at the end of a cable and taking data todetermine the resistance between these electrodes as afunction of depth. The water between the two cylindersforms a cylindrical shell of inner radius ra, outer radius n,and length L much larger than . The scientist applies apotential difference AV between the inner and outersurfaces, producing an outward radial current I. Let prepresent the resistivity of the water. (a) Find theresistance of the water between the cylinders in terms of L,p, Ta, and . (b) Express the resistivity of the water interms of the measured quantities L, ra, V. AV, and I.Figure P27.68

Answered: Image /qna-images/answer/3ddddf6a-ae40-4f3f-8c5c-453579721525.jpg

An oceanographer is studying how the ion concentration in sea water depends on depth. She does this by lowering into the water a pair of concentric metallic cylinders (Fig. P27.68) at the end of a cable and taking data to determine the resistance between these electrodes as a function of depth. The water between the two cylinders forms a cylindrical shell of inner radius ra, outer radius , and length L much larger than 7,. The scientist applies a potential difference AV between the inner and outer surfaces, producing an outward radial current L Let p represent the resistivity of the water. (a) Find the resistance of the water between the cylinders in terms of L, p. Ta, and . (b) Express the resistivity of the water in terms of the measured quantities L, ra, , AV, and I. Figure P27.68

An oceanographer is studying how the ion concentration in sea water depends on depth. She does this by lowering into the water a pair of concentric metallic cylinders (Fig. P27.68) at the end of a cable and taking data to determine the resistance between these electrodes as a function of depth. The water between the two cylinders forms a cylindrical shell of inner radius ra, outer radius , and length L much larger than 7,. The scientist applies a potential difference AV between the inner and outer surfaces, producing an outward radial current L Let p represent the resistivity of the water. (a) Find the resistance of the water between the cylinders in terms of L, p. Ta, and . (b) Express the resistivity of the water in terms of the measured quantities L, ra, , AV, and I. Figure P27.68

Physics for Scientists and Engineers: Foundations and Connections

1st Edition

ISBN:9781133939146

Author:Katz, Debora M.

Publisher:Katz, Debora M.

Chapter28: Current And Resistance

Section: Chapter Questions

Problem 69PQ

See similar textbooks

Similar questions

A 20 meter length of aluminum wire with diameter 1 cm carries a certain current load I when a potential difference V is applied across its ends while at 20oC. What diameter silver wire would be necessary to carry the same current under the same conditions?
(a) During surgery, a current as small as 20.0A applied directly to the heart may cause ventricular fibrillation. If the resistance of the exposed heart is 300 what is the smallest voltage that poses thisdanger? (b) Does your answer imply that special electrical safetyprecautions are needed?
Taking R = 1.00 k and = 250 V in Figure P27.19, determine the direction and magnitude of the current in the horizontal wire between a and e. Figure P27.19
Three equally long meter-long copper wires with diameters of 1 mm, 2 mm and 3 mm are connected in series and connected to a voltage of 12 V. How much current flows through the wires (I)? What are the stresses on the individual sections (U1, U2, U3)? (specific resistance of copper is 0.017 Vmm2/ Am)
A rectangular block of copper has sides of length 10. cm, 20. cm,and 40. cm. If the block is connected to a 6.0 - V source acrosstwo of its opposite faces, what are (a) the maximum currentand (b) the minimum current the block can carry?
Along the x axis, 3.57E16 electrons move from x = –1.00 m to x = 1.00 m in 9.25 s. What is the average current l through the origin x = 0.00 m (in A; use positive sign if l is in the +x direction, and negative sign if lis in the –x direction)?
Q2. To determine the galvanometer's internal resistor R. and its maximum electric current Is, corresponding to a maximum deviation of its needle, we mount it in series with a rheostat, as shown in the adjacent figure. R a b son Reosta Galvanometre When the needle makes a maximum deviation Vab = V1 = 5 V and Rr= R1 = 80 k 2. When the needle makes 1/2 maximum deviation Vab = V2 = 2 V and Rp = R2 = 60 ko. When the needle makes 44 maximum deviation Vab = V3 = 2 V and Rr = R3 . V a) Write the relationship between V1, R1, Rc and le. b) Write the relationship between V2, R2, Re and Ic. c) Write the relationship between V3, R3, Re and Ic. d) Determine the values of Re and Ic. e) Determine the value of Rs. Answer:
Kiting during a storm. The legend that Benjamin Franklin flew a kite as a storm approached is only a legend — he was neither stupid nor suicidal. Suppose a kite string of radius 2.10 mm extends directly upward by 0.802 km and is coated with a 0.520 mm layer of water having resistivity 155 Ω·m. If the potential difference between the two ends of the string is 176 MV, what is the current through the water layer? The danger is not this current but the chance that the string draws a lightning strike, which can have a current as large as 500 000 A (way beyond just being lethal).
Taking R = 1.00 kΩ and ε = 250 V in Figure P27.19, determine the direction andmagnitude of the current in the horizontal wire between a and e.Figure P27.19
A copper wire has a diameter of 2.0 mm and a length of 3.0 m. It carries acurrent of 6.3 A. The density of free electrons in copper is 8.5×1028electrons per cubic meter and resistivity of copper is 1.7×10-8Ω.m.a) What is the current density in the wire?b) What is the resistance of the wire?c) What is the electric field in the wire?d) What is the drift velocity of free electrons? Or calculatethe drift velocity of free electrons (or find the drift velocity of freeelectrons)e) Find the power dissipated as heat in the wire
(a) Find the equivalentresistance between pointsa and b in Figure P18.7.(b) Calculate the currentin each resistor if a potentialdifference of 34.0 V isapplied between points aand b.
An iron wire has a cross - sectional area of 5.00 x 10-6 m2.Carry out steps (a) through (e) to compute the drift speed ofthe conduction electrons in the wire. (a) How many kilogramsare there in 1 mole of iron? (b) Starting with the density of ironand the result of part (a), compute the molar density of iron(the number of moles of iron per cubic meter). (c) Calculatethe number density of iron atoms using Avogadro’s number.(d) Obtain the number density of conduction electrons giventhat there are two conduction electrons per iron atom. (e) Ifthe wire carries a current of 30.0 A, calculate the drift speed ofconduction electrons.