Concept explainers
Current materials-science technology allows engineers to construct capacitors with much higher values of C than were previously possible. A capacitor has C = 3000 F and is rated to withstand a maximum potential difference of 2.7 V. The cylindrical capacitor has diameter 6.0 cm and length 13.5 cm. (a) Find the maximum electric potential energy that can be stored in this capacitor, (b) Does your value in part (a) agree with the 3.0-Wh value printed on the capacitor? (c) What is the maximum attainable energy density in this capacitor? (d) Compare this maximum energy density to the maximum possible energy density for polyester (see Table 24.2).
Want to see the full answer?
Check out a sample textbook solutionChapter 24 Solutions
University Physics with Modern Physics (14th Edition)
Additional Science Textbook Solutions
The Cosmic Perspective Fundamentals (2nd Edition)
Conceptual Integrated Science
Applied Physics (11th Edition)
Essential University Physics (3rd Edition)
University Physics Volume 1
The Cosmic Perspective (8th Edition)
- (i) Rank the following five capacitors from greatest to smallest capacitance, noting any cases of equality, (a) a 20-F capacitor with a 4-V potential difference between its plates (b) a 30-F capacitor with charges of magnitude 90 C on each plate (c) a capacitor with charges of magnitude 80 C on its plates, differing by 2 V in potential. (d) a 10-F capacitor storing energy 125 J (e) a capacitor storing energy 250 J with a 10-V potential difference (ii) Rank the same capacitors in part (i) from largest to smallest according to the potential difference between the plates, (iii) Rank the capacitors in part (i) in the order of the magnitudes of the charges on their plates, (iv) Rank the capacitors in part (i) in the order of the energy they store.arrow_forwardThe dielectric to be used in a parallel-plate capacitor has a dielectric constant of 3.60 and a dielectric strength of 1.60107 V/m. The capacitor has to have a capacitance of 1.25 nF and must be able to withstand a maximum potential difference 5.5 kV. What is the minimum area the plates of the capacitor may have?arrow_forwardWhat If? The two capacitors of Problem 13 (C1 = 5.00 F and C2 = 12.0 F) are now connected in series and to a 9.00-Y battery. Find (a) the equivalent capacitance of the combination. (b) the potential difference across each capacitor, and (c) the charge on each capacitor.arrow_forward
- When a Leyden jar is charged by a hand generator (Fig. 27.1, page 828), the work done by the person turning the crank is stored as electric potential energy in the jar. When a capacitor is charged by a battery, where does the electric potential energy come from?arrow_forwardA parallel-plate capacitor is charged and then is disconnected from the battery. By what factor does the stored energy change when the plate separation is then doubled? (a) It becomes four times larger. (b) It becomes two times larger. (c) It stays the same. (d) It becomes one-half as large. (e) It becomes one-fourth as large.arrow_forwardA spherical capacitor consists of a spherical conducting shell of radius b and charge 2Q that is concentric with a smaller conducting sphere of radius a and charge +Q (Fig. P20.36). (a) Show that its capacitance is C=abke(ba) (b) Show that as b approaches infinity, the capacitance approaches the value a/ke = 40a. Figure P20.36arrow_forward
- (i) A battery is attached to several different capacitors connected in parallel. Which of the following statements is true? (a) All capacitors have the same charge, and the equivalent capacitance is greater than the capacitance of any of the capacitors in the group, (b) The capacitor with the largest capacitance carries the smallest charge, (c) The potential difference across each capacitor is the same, and the equivalent capacitance is greater than any of the capacitors in the group. (d) The capacitor with the smallest capacitance carries the largest charge. (e) The potential differences across the capacitors are the same only if the capacitances are the same, (ii) The capacitors are reconnected in series, and the combination is again connected to the battery. From the same choices, choose the one that is true.arrow_forwardAn electric potential exists in a region of space such that V = 8x4 2y2 + 9z3 and V is in units of volts, when x, y, and z are in meters. a. Find an expression for the electric field as a function of position. b. What is the electric field at (2.0 m, 4.5 m, 2.0 m)?arrow_forward(a) Regarding (lie Earth and a cloud layer 800 m above the Earth as the plates of a capacitor, calculate the capacitance of the Earth-cloud layer system. Assume the cloud layer has an area of 1.00 km2 and the air between the cloud and the ground is pure and dry'. Assume charge builds up on the cloud and on the ground until a uniform electric field of 3.00 106 N/C throughout the space between them makes the air break down and conduct electricity as a lightning bolt, (b) What is the maximum charge the cloud can hold?arrow_forward
- A variable air capacitor used in a radio tuning circuit is made of N semicircular plates, each of radius R and positioned a distance d from its neighbors, to which it is electrically connected. As shown in Figure P20.38, a second identical set of plates is enmeshed with the first set. Each plate in the second set is halfway between two plates of the first set. The second set can rotate as a unit. Determine the capacitance as a function of the angle of rotation , where = 0 corresponds to the maximum capacitance. Figure P20.38arrow_forwardEarth can be considered as a spherical capacitor with two plates, where the negative plate is the surface of Earth and the positive plate is the bottom of the ionosphere, which is located at an altitude of approximately 70 km. The potential difference between Earth’s surface and the ionosphere is about 350,000 V. (a) Calculate the capacitance of this system, (b) Find the total charge on this capacitor, (c) Find the energy stored in this system.arrow_forwardAccording to UE=12C(V)2 (Eq. 27.3), a greater capacitance means more energy is stored by the capacitor, but according to UE = Q2/2C (Eq. 27.2), a greater capacitance means less energy is stored. How can both of these equations be correct?arrow_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 LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
- Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning