Parallel Plate Capacitors

A uniform electric field is established by connecting the plates of a parallel-plate capacitor to a 12-V battery. A) If the plates are seperated by 0.75 cm, what is the magnitude of the electric field in the capacitor? B) A charge of +6.24 x 10 -6 C moves from the positive plate to the negative plate. Find the change in electric potential energy for this charge.

The charge on the square plates of a parallel-plate capacitor is Q. The potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. The amount of charge on the plates is now equal to (a) Q/2. (b) Q. (c) Q/4. (d) 2Q. (e) 4Q.

Two parallel-plate capacitors C1 and C2, are separated by vacuum. C1 plate has an area twice as large as C2, but the plates of C1 are separated by a distance 1/3 that of C2. What is the ratio of their capacitance (C1: C2)? A) 1:6 B) 6:1 C) 2:3 D) 3:2

Consider a parallel-plate capacitor constructed from two circular metal plates of radius R. The plates are separated by a distance of 1.5 mm. (a) What radius must the plates have if the capacitance of this capacitor is to be 1.0 μF? (b) When the capacitor is connected to a 12.0-V battery, what is the magnitude of the charge on each of the plates? (c) Find the energy stored in the capacitor.

A parallel plate capacitor has plates with area A = 350cm2 separated by a distance d = 1.5mm. What is the capacitance when the capacitor is filled with air?  

You reposition the two plates of a parallel-plate capacitor so that the distance between them doubles. There is vacuum between the plates. If the charges +Q and -Q on the two plates are kept constant in this process, which of the following statements is incorrect? A) The potential difference between the two plates doubles. B) The electric field between the two plates keeps the same. C) The potential energy stored in this capacitor doubles. D) The capacitance of this capacitor doubles. 

Each plate of a parallel-plate air capacitor has an area of 0.0010 m 2, and the separation of the plates is 0.050 mm. An electric field of 7. 4x10   6 V/m is present between the plates. The capacitance of the capacitor, in pF, is closest to: A) 180 B) 300 C) 240 D) 120 E) 360

The plates of a parallel-plate capacitor are 3.0mm apart, and each plate carries 75nC of charge. The electric field between the plates has a magnitude of 3.5 x 106V/m. The plates are in vacuum. a) What is the potential difference between the plates? b) What is the capacitance? c) What is the area of each plate?

The potential difference between the plates of a parallel plate capacitor with the plate separation of 6 mm is 60 V. What is the electric field between the plates of this capacitor?A) 500 V/mB) 1000 V/mC) 2000 V/mD) 60 V/m

What property of objects is best measured by their capacitance?a) ability to conduct electric currentb) ability to distort an external electrostatic fieldc) ability to store charge

Consider an air-filled charged parallel plate capacitor. How can its capacitance be increased?a) Increase the charge on the capacitor.b) Decrease the charge on the capacitor.c) Increase the spacing between the plates of the capacitor.d) Decrease the spacing between the plates of the capacitor.e) Increase the length of the wires leading to the capacitor plates.

(a) Assume that charge −q is placed on the top plate, and +q is placed on the bottom plate. What is the magnitude of the electric field E between the plates? Express E in terms of q and other quantities given in the image, in addition to ε0 and any other constants needed.(b) What is the voltage V between the plates of the capacitor? Express V in terms of the quantities given in the image and any required physical constants.(c) Now find the capacitance C of the parallel-plate capacitor. Express C in terms of quantities given in the image and constants like ε0.

Describe qualitatively but specifically how the circuit quantities change after the switch is closed in the circuit a) current b) voltage across the capicitor. Explain why these quantities change as they do, in terms of motion and presence of the capacitor.

Two 2.10 cm × 2.10 cm plates that form a parallel-plate capacitor are charged to ± 0.708 nC.Part AWhat is the electric field strength inside the capacitor if the spacing between the plates is 2.60 mm?Part BWhat is the potential difference across the capacitor if the spacing between the plates is 2.60 mm?Show your work.

A large capacitor has a charge + on one plate and on the other. At time t = 0, the capacitor is connected in series to two ammeters and a light bulb. Immediately after the circuit is closed, the ammeter connected to the positive plate of the capacitor reads Ip and the ammeter connected to the negative plate of the capacitor reads IN. (Figure 1) Each ammeter reads positive if current flows through the circuit in a clockwise direction (from the + to the terminal of the meter).Part A Immediately after time t = 0, what happens to the charge on the capacitor plates? A) Individual charges flow through the circuit from the positive to the negative plate of the capacitor.B) Individual charges flow through the circuit from the negative to the positive plate of the capacitor. C) The positive and negative charges attract each other, so they stay in the capacitor. D) O Current flows clockwise through the circuit. E) Current flows counterclockwise through the circuit.Part B At any given instant after t = 0, what is the relationship between the current flowing through the two ammeters, Ip and In, and the current through the bulb, IB?A) Ip > IB > IN B) Ip = IB >  IN C)  Ip > IB  = IN D) Ip= IB = IN 

You can increase the capacitance of a capacitor by A. Decreasing the plate spacing B. Increasing the plate spacing.  C. Decreasing the area of the plates. D. Increasing the area of the plates. E. Both A and D F. Both B and C

Two 2.50 cm × 2.50 cm plates that form a parallel-plate capacitor are charged to ± 0.708 nC.a) What is the potential difference across the capacitor if the spacing between the plates is 3.00 mm?b) What is the electric field strength inside the capacitor if the spacing between the plates is 3.00 mm?

Two 2.50 cm × 2.50 cm plates that form a parallel-plate capacitor are charged to ± 0.708 nC.a) What is potential difference across the capacitor if the spacing between the plates is 1.50 mm?b) What is the electric field strength inside the capacitor if the spacing between the plates is 1.50 mm?

A 5.00μF parallel-plate capacitor is connected to a 12.0 V battery. After the capacitor is fully charged, the battery is disconnected without loss of any charge on the plates. (a) A voltmeter is connected across the two plates without discharging them. What does it read? (b) what would the voltmeter read if (i) the plate separation was doubled; (ii) the radius of each plate were doubled but their separation was unchanged?

A parallel-plate capacitor is formed from two 9.1 cm-diameter electrodes spaced 1.1 mm apart. The electric field strength inside the capacitor is 6.0×106 N/C. What is the charge (in nC) on each electrode?

Two 2.0-cm-diameter disks face each other, 1.0 mm apart. They are charged to ±10 nC.a) What is the electric field strength between the disks?b) A proton is shot from the negative disk toward the positive disk. What launch speed must the proton have to just barely reach the positive disk?

Two 2.90 cm × 2.90 cm plates that form a parallel-plate capacitor are charged to ± 0.708 nC. The electric field is 95082 V/m.What is the potential difference across the capacitor if the spacing between the plates is 3.00 mm ? 

You have two identical capacitors and an external potential source.Energy storage in a capacitor can be limited by the maximum electric field between the plates. What is the ratio of the electric field for the series and parallel combinations?E(parallel)/E(series) =?

The three configurations shown below are constructed using identical capacitors1) Which of these configurations has the lowest overall capacitance? a) A b) B c) Cd) All three configurations have the same capacitance 2) Briefly explain your reasoning

The two configurations shown below are constructed using identical capacitors. 1) Which of these configurations has the lowest overall capacitance? a) A b) B c) Both configurations have the same capacitance2) Briefly explain your reasoning

Which of the following will increase the capacitance of a parallel-plate capacitor?Check all that apply.a) Increasing the area of the plates will increase the capacitance of a parallel-plate capacitor.b) Decreasing the area of the plates will increase the capacitance of a parallel-plate capacitor.c) Decreasing the separation between the plates will increase the capacitance of a parallel-plate capacitor.d) Increasing the separation between the plates will increase the capacitance of a parallel-plate capacitor.

(a) What is the equivalent capacitance for the circuit of the figure?(b) What is the charge of the capacitor 4.0 μF?(c) What is the charge of the capacitor 2.0 μF?(d) What is the charge of the capacitor 1.0 μF?

A system of four capacitors are connected across a 90 -V voltage source as shown in the figure. a) What is the charge on 4.0 uF capacitor? b) What is the charge on 2.0 uF capacitor? 

Consider a charged parallel-plate capacitor. Which combination of changes would quadruple its capacitance?a) Double the charge and double the plate area.b) Double the charge and double the plate separation.c) Halve the charge and double the plate separation.d) Halve the charge and double the plate area.e) Halve the plate separation; double the plate area.f) Double the plate separation; halve the plate area.

A parallel-plate air capacitor has a capacitance of 920 pF. The charge on each plate is 3.90 μC. What is the potential difference between the plates? Express your answer with the appropriate units. Part B If the charge is kept constant, what will be the potential difference between the plates if the separation is doubled? Express your answer with the appropriate units. Part C How much work is required to double the separation? Express your answer with the appropriate units (mJ)

A system of four capacitors are connected across a 90 -V voltage source as shown in the figure. a) What is the potential difference across the plates of the 6.0 uF capacitor? b) What is the charge on the 3.0 uF capacitor?

A parallel-plate capacitor is charged by a 17.0 V battery, then the battery is removed. What is the potential difference between the plates after the battery is disconnected? What is the potential difference between the plates after a sheet of Teflon is inserted between them?

A 2.0-cm-diameter parallel-plate capacitor with a spacing of 0.50 mm is charged to 200 V?Part A. What is the total energy stored in the electric field? Express your answer using two significant figures.U=______ Part B. What is the energy density. Express your answer using two significant figures.u = ________

Consider a parallel plate capacitor having plates of area 0.000495 m2 that are separated by 0.085 mm of Teflon. The dielectric constant of Teflon is K = 2.1. Find the capacitance in F.

Two 2.90 cm × 2.90 cm plates that form a parallel-plate capacitor are charged to ± 0.708 nC .What is potential difference across the capacitor if the spacing between the plates is 1.50 mm ?

Two 2.90 cm × 2.90 cm plates that form a parallel-plate capacitor are charged to ± 0.708 nC .What is the electric field strength inside the capacitor if the spacing between the plates is 3.00 mm ?

What is the time constant for the discharge of the capacitors in the figure (Figure 1)?