Capacitors: Electric Charge

Satisfactory Essays
2010 회로 및 전자기학 숙제 #2
제출 2010년 3월 19일 (금) C319
1. Three point charges Q1  9 C , Q2  4 C , Q3  36 C are arranged on a straight line. The distance between Q1 and Q3 is 9cm. It is claimed that a location can be selected for Q2 such that each charge will experience a zero force. Find this location. 2. A line charge of uniform charge density

l

forms a circle of radius b that lies in the

xy-plane in air with its center at the origin.



a) Find the electric field intensity E at the point (0, 0, h).



b) At what value of h will E in part (a) be a maximum? What is this maximum?

3. Determine the work done in carrying a

 5 C charge from P1 ( 1, 2,  4) to

 

P2 (2, 8,  4) in the field E  a x y  a y x
a) along the parabola y  2x , and
2

b) along the straight line joining P and P2 .
1

4. A finite line charge of length L carrying uniform line charge density

l

is coincident

with x-axis.
a) Determine V in the plane bisecting the line charge.



b) Determine E from

l

directly by applying Coulomb’s law.

5. The polarization in a dielectric cube of side L centered at the origin is given by





P  P0 (a x x  a y y  a z z ) .
a) Determine the surface and volume bound-charge densities.
b) Show that the total bound charge is zero.

6. The space between a parallel-plate capacitor of area S is filled with a dielectric whose permittivity varies linearly from

1

at one plate (y=0) to

2

at the other plate

(y=d). Neglecting fringing effect, find the capacitance.

7. Three capacitors

1 C , 2 C , and 3 C are connected as shown in Figure across a

240-volt source. Calculate the electric energy stored in each capacitor.

1F
2 F
3F

+

-

240(V)

8. A parallel-plate capacitor of width w, length L, and separation d has a solid dielectric slab of permittivity



in the space between the plates. The capacitor is charged to a

voltage V0 by a

You May Also Find These Documents Helpful

  • Good Essays

    Electric Charge

    • 376 Words
    • 2 Pages

    Electricity is the force that holds together the molecules and atoms of all substances. The type of electricity that is most familiar to us is electrical current. This is the flow of electrical charges through a substance called a conductor such as a metal wire. This flow happens beacuse some of the negatively charge electrons circling the nuclei of the conductor's are held loosely. The electrons can move from one atom to the next, producing and electrical current. Electricity has become something we…

    • 376 Words
    • 2 Pages
    Good Essays
  • Satisfactory Essays

    Electric Charge

    • 342 Words
    • 2 Pages

    relationship between the electric potential at a point in space and the distance from an electric charge? 1) Place a positive 1 nano-coulomb charge on the screen. 2) Turn on “Show numbers” 3) Turn on “tape measure”. 4) Use the tape measure to find and record the distance from the charge to the equipotential sensor. 1.88 m 5) Record the voltage as indicated on the equipotential sensor. 4.1v 6) Change the location of the positive charge to at least six widely different…

    • 342 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    Electric Charge

    • 1344 Words
    • 6 Pages

    HW 1 solutions Point Charge in One Dimension A point charge q1 = -3.5 μC is located at the origin of a co-ordinate system. Another point charge q2 = 5.1 μC is located along the x-axis at a distance x2 = 9.3 cm from q1. 1) What is F12,x, the value of the x-component of the force that q1 exerts on q2? -18.57 N For all of these problems we want to make use of the standard electric force equation: ̂ So for this problem with K=9*109 Nm2/C2, Q1=-3.5μC, Q2=5.1 μC, and r=9.3 cm we get F=-18.57…

    • 1344 Words
    • 6 Pages
    Satisfactory Essays
  • Good Essays

    Electric Charge

    • 605 Words
    • 3 Pages

    each other. The evidence showed that electric force made matter either attract or repel other matter. Electric force is caused by electric charge. Electric charge is a property of the bits of matter within atoms. Electric force can cause matter to attract or repel because there are two kinds of charge – positive and negative charge. The effects of electric force can be summarized as the law of electric charge: Pieces of matter with the same kind of charge repel each other. Pieces of matter…

    • 605 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    5: Electric Charge

    • 430 Words
    • 2 Pages

    What happened to the test charge when brought near another positive charge and how did you use this fact to score a goal only using positive charges? Explain for both the practice charge and more difficult levels. ● The charge was propelled away from the positive charge. On harder levels , I put the positive charges on the outside path d the test charge to take. 2. What happened to the test charge when brought near a negative charge and how did you use this fact to score a goal only using negative charges? Explain for both the practice…

    • 430 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    The electron is a fundamental subatomic particle that carries a negative electric charge. It is a spin-½ lepton that participates in electromagnetic interactions, and its mass is less than one thousandth of that of the smallest atom. Its electric charge is defined by convention to be negative, with a value of −1 in atomic units. Together with atomic nuclei, electrons make up atoms; their interaction with adjacent nuclei is the main cause of chemical bonding. The name "electron" comes from…

    • 526 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Types of Electric Charge

    • 1514 Words
    • 7 Pages

    Ch.9.1 – Types of Electric Charge * Static electricity : static cling of clothes out of dryer; lightning; * Walk across carpet and touch get a shock touching metal doorknob – friction of shoes against carpet cause you acquire static electric charge * Static charge – electric charge at rest, stays on and eventually discharged or lost to other objects/air * Discharge – remove excess static charge so the object is neutral * Static charge last long when air is dry * Electrostatics…

    • 1514 Words
    • 7 Pages
    Good Essays
  • Good Essays

    Electric Charge Lab

    • 612 Words
    • 3 Pages

    Electric Charge Lab John Doe Physics 1130 Oct 26th, 2010 Objective In this lab we will investigate some properties of electric charge, conductors, and insulators using everyday objects. Theory A charged object is any object that has an excess of negative or positive charge. Most objects are neutrally charged and we don’t normally experience their charge properties. Rubbing objects together and transferring some charge from one to the other is one way to create charged objects. Like charges…

    • 612 Words
    • 3 Pages
    Good Essays
  • Powerful Essays

    Electric Charge and Electric Field:-> 1. Electric Charge Electric charge is a fundamental property like mass, length etc associated with elementary particles for example electron, proton and many more. Electric charge is the property responsible for electric forces which acts between nucleus and electron to bind the atom together. Charges are of two kinds (i) negative charge (ii) positive charge Electrons are negatively charged particles and protons, of which nucleus is made of,…

    • 1713 Words
    • 7 Pages
    Powerful Essays
  • Good Essays

    Capacitors

    • 993 Words
    • 4 Pages

    their existence is what is called a "capacitor." Many people have heard the word capacitor, but also many do not even have an idea of what it means or what is the use for it. In this research, I will concentrate on explaining the physics of a capacitor and describing the main types of capacitors that exist today. A capacitor is a device used to store charge in an electrical circuit. The function of a capacitor is much similar to a battery, but it charges and discharges much more efficiently…

    • 993 Words
    • 4 Pages
    Good Essays