Part A A parallel-plate vacuum capacitor has 6.18 J of energy stored in it. The separation between the plates is 3.90 mm . If the separation is decreased to 1.40 mm , what is the energy now stored if the capacitor was disconnected from the potential source before the separation of the plates was changed? U = J Submit Request Answer Part B What is the energy now stored if the capacitor remained connected to the potential source while the separation of the plates was changed? να ΑΣφ U = J

Part A A parallel-plate vacuum capacitor has 6.18 J of energy stored in it. The separation between the plates is 3.90 mm . If the separation is decreased to 1.40 mm , what is the energy now stored if the capacitor was disconnected from the potential source before the separation of the plates was changed? U = J Submit Request Answer Part B What is the energy now stored if the capacitor remained connected to the potential source while the separation of the plates was changed? να ΑΣφ U = J

Physics for Scientists and Engineers: Foundations and Connections

1st Edition

ISBN:9781133939146

Author:Katz, Debora M.

Publisher:Katz, Debora M.

Chapter27: Capacitors And Batteries

Section: Chapter Questions

Problem 88PQ: A parallel-plate capacitor has square plates of side s = 2.50 cm and plate separation d = 2.50 mm....

See similar textbooks

Similar questions

In a certain region of space, the electric field is zero. From this fact, what can you conclude about the electric potential in this region? (a) It is zero, (b) It does not vary with position. (c) It is positive. (d) It is negative. (e) None of those answers is necessarily true.
An air-filled capacitor is made from two flat parallel plates 1.0 mm apart. The inside area of each plate is 8.0cm2. (a) What is the capacitance of this set of plates? (b) If the region between the plates is filled with a material whose dielectric constant is 6.0, what is the new capacitance?
Unreasonable Results (a) An 8.00 F capacitor is connected in parallel to another capacitor, producing a total capacitance of 5.00 F. What is the capacitance of the second capacitor? (b) What is unreasonable about this result? (C) Which assumptions are unreasonable or inconsistent?
A spherical capacitor is formed from two concentric spherical conducting spheres separated by vacuum. Tire inner sphere has radius 12.5 cm and the outer sphere has radius 14.8 cm. A potential difference of 120 V is applied to the capacitor, (a) What is the capacitance of the capacitor? tb) What is the magnitude of the electrical field at r = 12.6 cm, just outside the inner sphere? (c) What is the magnitude of the electrical field at r = 14.7 cm, just inside the outer sphere? (d) For a parallel-plate capacitor the electrical field is uniform in the region between the plates, except near the edges of the plates. Is this also true for a spherical capacitor?
When a 360-nF air capacitor is connected to a power supply, the energy stored in the capacitor is 18.5J . While the capacitor is connected to the power supply, a slab of dielectric is insetted that completely fills die space between the plates. This increases the stored energy by 23.2J . (a) What is the potential difference between the capacitor plates? (b) What is die dielectric constant of the slab?
(a) An 8.00/F capacitor is connected in parallel to another capacitor, producing a total capacitance of 5.00/F . What is the capacitance of the second capacitor? (b) What is unreasonable about this result? (c) Which assumptions are unreasonable or inconsistent?
A parallel-plate capacitor with plates of area LW and plate separation t has the region between its plates filled with wedges of two dielectric materials as shown in Figure P25.48. Assume t is much less than both L and W. (a) Determine its capacitance. (b) Should the capacitance be the same if the labels 1 and 2 are interchanged? Demonstrate that your expression does or does not have this property. (c) Show that if 1 and 2 approach equality to a common value , your result becomes the same as the capacitance of a capacitor containing a single dielectric: C = 0LW/t. Figure P25.48
a parallel-plate capacitor with area 0.200 m2 and plate separation of 3.00 mm is connected to a 6.00-V battery. (a) What is the capacitance? (b) How much charge is stored on the plates? (c) What is the electric field between the plates? (d) Find the magnitude of the charge density on each plate. (e) Without disconnecting the battery, the plates are moved farther apart. Qualitatively, what happens to each of the previous answers?
A spherical capacitor is formed from two concentric spherical conducting shells separated by a vacuum. The inner sphere has radius 12.5 cm and the outer sphere has radius 14.8 cm. A potential difference of 120 V is appLied to the capacitor, (a) What is the energy density at r = 12.6 cm, just outside the inner sphere? (b) What is the energy density at r = 14.7 cm, just inside the outer sphere? (c) For the parallel-plate capacitor the energy density is uniform in the region between the plates, except near the edges of the plates. Is this also true for the spherical capacitor?
A parallel-plate capacitor has capacitance 3.00 F. (a) How much energy is stored in the capacitor if it is connected to a 6.00-V battery? (b) If the battery is disconnected and the distance between the charged plates doubled, what is the energy stored? (c) The battery is subsequently reattached to the capacitor, but the plate separation remains as in part (b). How much energy is stored? (Answer each part in microjoules.)
Why is it dangerous to touch the terminals of a high-voltage capacitor even after the voltage source that charged the capacitor is disconnected from the capacitor? (b) What can be done to make the capacitor safe to handle after the voltage source has been removed?
True or False? (a) From the definition of capacitance C = Q/V it follows that an uncharged capacitor has a capacitance of zero. (b) As described by the definition of capacitance, the potential difference across an uncharged capacitor is zero.