Concept explainers
BIO SPIDERWEB
*Based on F. Vollrath and D. Edmonds. “Consequences of electrical conductivity in an orb spider’s capture web.” Natunvissenschaften (100:12. December 2013, pp. 1163-69).
25.82 In another experiment, a piece of the web is suspended so that it can move freely. When either a positively charged object or a negatively charged object is brought near the web, the thread is observed to move toward the charged object. What is the best interpretation of this observation? The web is (a) a negatively charged conductor; (b) a positively charged conductor; (c) either a positively or negatively charged conductor; (d) an electrically neutral conductor.
Learn your wayIncludes step-by-step video
Chapter 25 Solutions
University Physics with Modern Physics (14th Edition)
Additional Science Textbook Solutions
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
Essential University Physics (3rd Edition)
University Physics Volume 2
Lecture- Tutorials for Introductory Astronomy
The Cosmic Perspective
Glencoe Physical Science 2012 Student Edition (Glencoe Science) (McGraw-Hill Education)
- Two conducting wires A and B of the same length and radius are connected across the same potential difference. Conductor A has twice the resistivity of conductor B. What is the ratio of the power delivered to A to the power delivered to B? (a) 2 (b) 2 (c) 1 (d) 12 (e)12arrow_forwardA potential difference of 3.00 nV is set up across a 2.00 cm length of copper wire that has a radius of 2.00 mm. How much charge drifts through a cross section in 3.00 ms?arrow_forwardA cylindrical copper wire transmits a charge of 360 °C in 10 minutes. Copper, 8.5x10^28 free per cubic metercontains electrons. If the radius of the wire is I mm, what is the drift velocity of the electrons (in mm's)(take e=1.6x10^-19 C, pi=3) ? A) 0.015 B) 0.055 C) 0.045 D) 0.025 E) 0.035arrow_forward
- 67. A straight, cylindrical wire lying along the x axis has a length of 0.500 m and a diameter of 0.200 mm. It is made of a material described by Ohm’s law with a resistivity of r 5 4.00 3 1028 V ? m. Assume a poten- tial of 4.00 V is maintained at the left end of the wire at x 5 0. Also assume V 5 0 at x 5 0.500 m. Find (a) the magnitude and direction of the electric field in the wire, (b) the resistance of the wire, (c) the magnitude and direction of the electric current in the wire, and (d) the current density in the wire. (e) Show that E 5 rJ.arrow_forward1. Given a cylindrical conductor of radius 1.50 mm with current density 2.50A/m^2 and free-electron density of 8.00×10^ 28 m^−3 What is the drift speed? 2. A parallel plate capacitor is connected to an ideal battery with voltage V. While the battery is still connected, a slab with dielectric constant κ is inserted between the plates. Which of the following is TRUE regarding the electric field E and the stored energy U?arrow_forwardConsider a wire made of copper with conductivity 6.0 × 107 Ω-1m-1, which has a circular cross-section of radius 0.79 mm. In a particular circuit, this wire carries a current of 4.5 A. a. What is the electric field, in volts per meter, inside this wire? b. If we replace this wire with a gold one of the same size, with conductivity 4.1 × 107 Ω-1m-1, what will the electric field in the wire be?arrow_forward
- A rod of semiconducting material of lenght L=3 m and cross-sectional area A=4.5 mm^2 lies along the x-axis between x=0 and x=L. The material obeys ohm's law, and resistivity varies along the rod according to p=p0 (1-(x^2/L^2)) where p0= 4.10^-4 ohm.m. The end of the rod x=0 is at a potential V0=30V greater than the x=L. A) what is the total resistance, in units of ohm, of the rod? B) what is the current, in units of miliamperes, in the rod? C) what is the electric potential, in units of Volt, in the rod at x=L/2? D) what is the electic-field magnitude E, in units of V/m, in the rod at x=L/2?arrow_forwardThe plane of a square loop of wire with edge length a=0.200m is oriented Vertically and along an east west axis. The Earth’s magnitude field at this Points is of magnitude B=35.0 µT and is directed north ward at 35.0° below The horizontal.The total resistance of the loop and the wires connecting it To a sensitive ammeter is 0.500Ω. If the loop is suddenly collapsed by horizontal Forces are shown in figure p30.37, what total charge enters one terminal of the Ammeter?arrow_forwardIf a defibrillator passes 20A of current through a patients’ body for an interval of 10 seconds. How much chargepasses through the patient’s skin?a) 3.2 x 10-17 Cb) 3.2 x 10-18 Cc) 200 Cd) 20 Ce) 2 Carrow_forward
- What is the magnitude of the flow speed of the charge carriers (mm/s)? Diameter=1.5 mm I=2.01 A There are 8.5×1028 free electrons in copper per cubic meter and cross-sectional area is 1.767μm2arrow_forwardA typical lightning bolt may last for 0.152 s and transfer 1.15 ✕ 1020 electrons. Calculate the average current (in A) in the lightning bolt. HINTarrow_forwardThe voltage across a membrane forming a cell wall is 76.0 mV and the membrane is 8.80 nm thick. What is the electric field strength in volts per meter? (The value is surprisingly large, but correct. Membranes are discussed later in the textbook.) You may assume a uniform E-field.___v/marrow_forward
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning