Material with uniform resistivity ρ is formed into a wedge as shown in Figure P27.84. Show that the resistance between face A and face B of this wedge is
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Physics for Scientists and Engineers with Modern, Revised Hybrid (with Enhanced WebAssign Printed Access Card for Physics, Multi-Term Courses)
- 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 P27.19arrow_forwardThe resistance between terminals a and b in Figure P27.36 is 75.0 . If the resistors labeled R have the same value, determine R. Figure P27.36arrow_forwardA battery is used to charge a capacitor through a resistor as shown in Figure P27.44. Show that half the energy supplied by the battery appears as internal energy in the resistor and half is stored in the capacitor. Figure P27.44arrow_forward
- For the purpose of measuring the electric resistance of shoes through the body of the wearer standing on a metal ground plate, the American National Standards Institute (ANSI) specifies the circuit shown in Figure P27.14. The potential difference AVacross the 1.00-M2 resistor is measured with an ideal voltmeter. (a) Show that the resistance of the footwear is 50.0 V – AV shoes AV (b) In a medical test, a current through the human body should not exceed 150 µA. Can the current delivered by the ANSI-specified circuit exceed 150 µA? To decide, consider a person standing barefoot on the ground plate. 1.00 MN V 50.0 V Figure P27.14arrow_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_forwardYou are working with an oceanographer who is studying how the ion concentration in seawater depends on depth. She shows you the device that she uses to measure the resistivity of water from a boat. It consists of a pair of concentric metallic cylinders at the end of a cable (as shown). Seawater flows freely between the two cylindrical shells. She makes a measurement by lowering the device into the water and applying a potential difference ΔV between the inner and outer cylinders. This produces an outward radial current I in the seawater between the shells. She shows you the current and voltage data for the water at a particular depth and is then called away to answer a long call on her cellphone about a laboratory issue back on the mainland. As she leaves, she says, “Have the resistivity of the water calculated when I get back.” She forgot to show you any tables or formulas to use to determine the resistivity, so you are on your own. Quick! Find an expression for the resistivity in…arrow_forward
- a.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_forwardThe circuit in Figure P27.41 contains two resistors, R1 = 2.00 kΩ and R2 = 3.00 kΩ, and two capacitors, C1 = 2.00 μF and C2 = 3.00 μF, connected to a battery with emf ε = 120 V. If there are no charges on the capacitors before switch S is closed, determine the charges on capacitors (a) C1 and (b) C2 as functions of time, after the switch is closed.arrow_forwardTwo cylindrical rods, one copper (resistivity 1.72 x 10-8 Q-m) and the other iron (resistivity 9.7 x 10-8 Q-m), are identical in lengths and cross-sectional areas. They are joined end to end to form one long rod. A 12-V battery is connected across the free ends of the copper- iron rod. What is the voltage between the ends of the copper rod? Vcu Number i Save for Later Units L Attempts: 0 of 3 used Submit Answerarrow_forward
- Air isn’t a perfect electric insulator, but it has a very high resistivity. Dry air has a resistivity of approximately 3 x 1013 Ω • m. A capacitor has square plates 10 cm on a side separated by 1.2 mm of dry air. If the capacitor is charged to 250 V, what fraction of the charge will flow across the air gap in 1 minute? Make the approximation that the potential difference doesn’t change as the charge flows.arrow_forwardIn a physics project, you need a wire to electrically heat a cryostat. You decide to create one with materials you have lying around. You find a 29.0-g piece of copper. The resistivity of copper is 1.68 x 10-8 Ω.m, and its density is 8.9 g/cm3. You will need to use all of your copper to create a solid cylindrical wire that has a total resistance of 0.75 Ω.Determine how long your wire will be, and what its diameter will be.arrow_forwardWire C and wire D are made from different materials and have length LC = LD = 4.3 m. The resistivity and diameter of wire C are 3.4 × 10-6 Ω·m and 1.15 mm, and those of wire D are 1.1 × 10-6 Ω·m and 0.78 mm. The wires are joined as shown in the figure and a current of 4.9 A is set up in them. What is the electric potential difference between (a) points 1 and 2 and (b) points 2 and 3? What is the rate at which energy is dissipated between (c) points 1 and 2 and (d) points 2 and 3?arrow_forward
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