The student engineer of a campus radio station wishes to verify the effectiveness of the lightning rod on the antenna mast (Fig. P27.49). The unknown resistance Rx is between points C and E. Point E is a true ground, but it is inaccessible for direct measurement because this stratum is several meters below the Earth’s surface. Two identical rods are driven into the ground at A and B, introducing an unknown resistance Ry. The procedure is as follows. Measure resistance R1 between points A and B, then connect A and B with a heavy
Figure P27.49
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Chapter 27 Solutions
Physics for Scientists and Engineers
- 1.00 MQ A conducting sphere is charged by an emf source E through a 1.00 MO resistor. When the sphere is fully charged, it has 2 µC charge. The highest current during the charging was I mA. What is the electrical potential energy of the sphere when it is fully charged? Give your answer in mJ.arrow_forwardThe average resistivity of the human body (apart from sur face resistance of the skin) is about 5.0 Ω • m. The conducting path between the right and left hands can be approximated as a cylinder 1.6 m long and 0.10 m in diameter. The skin resistance can be made negligible by soaking the hands in salt water.a. What is the resistance between the hands if the skin resistance is negligible?b. If skin resistance is negligible, what potential difference between the hands is needed for a lethal shock current of 100 mA? Your result shows that even small potential differences can produce dangerous currents when skin is damp.arrow_forwardMaterial with uniform resistivity p is formed into a wedge as shown in Figure P26.50. Show that the resistance between face A and face B of this wedge is L R= p In w(y2 – y,) Face A Face B Figure P26.50arrow_forward
- A cell membrane has a resistance and a capacitance and thus a characteristic time constant. What is the time constant of a 9.0-nm-thick membrane surrounding a 0.040-mm-diameter spherical cell?arrow_forwardTwo conductors are made of the same material and have the same length. Conductor A is a solid wire of diameter 1.1 mm. Conductor B is a hollow tube of outside diameter 2.5 mm and inside diameter 1.4 mm. What is the resistance ratio RA/RB., measured between their ends? Number Unitsarrow_forwarda.Estimate the electrical resistance of the blood in a 50cm long, 3mm diameter artery. The resistivity of blood is 1.6 ohm-meter.Express your answer in cΩ, mΩ,μΩ, and nΩ. B. Suppose the energy for two doughnuts in Thermodynamics are totally converted into electric potential energy at point a, wherein a dust particle of 5 × 10-9 kg with 9nC charge is travelling from point a with 600 m/s to point b (where there is no electric potential energy). How fast does the dust particle is moving at point b?arrow_forward
- 1.00 MQ A conducting sphere is charged by an emf source E through a 1.00 MQ resistor. When the sphere is fully charged, it has 1 µC charge. The highest current during the charging was 1 mA. What is the radius of the sphere in meters?arrow_forwardWhat is the time constant of the circuit shown in Figure OQ28.7? Each of the five resistors has resistance R. and each of the five capacitors has capacitance C. The internal resistance of the battery is negligible. (a) RC. (b) 5RC. (c) 10RC (d) 25RC (e) none of those answersarrow_forwardNerve impulses are carried along axons, the elongated fibers that transmit neural signals. We can model an axon as a tube with an inner diameter of 10 μm. The tube wall is insulated, but the fluid inside it has a resistivity of 0.50 Ω⋅m. What is the resistance of a 7.0- mm -long axon?Express your answer with the appropriate units.arrow_forward
- Subj : Electrostatics and Electricityarrow_forwardIn the circuit shown in Figure OQ28.12, each battery is delivering energy to the circuit by electrical transmission. All the resistors have equal resistance. (i) Rank the electric potentials at points a, b. c, d, and e from highest to lowest, noting any cases of equality in the ranking. (ii) Rank the magnitudes of the currents at the same points from greatest to least, noting any cases of equality.arrow_forwardA coaxial cable consists of two concentric cylindrical conductors. The region between the conductors is completely filled with polyethylene plastic as shown in the figure. The radius of the inner conductor is a= 0.6 cm, the radius of the outer conductor is b = 1.8 cm, and the length is L= 30 cm. The resistivity of the plastic is p= 1013 n. m Calculate the resistance of the plastic between the two conductors. Inner Outer conductor conductorarrow_forward