All Matches
Solution Library
Expert Answer
Textbooks
Search Textbook questions, tutors and Books
Oops, something went wrong!
Change your search query and then try again
Toggle navigation
FREE Trial
S
Books
FREE
Tutors
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Ask a Question
Search
Search
Sign In
Register
study help
physics
electricity and magnetism
Questions and Answers of
Electricity and Magnetism
Explain why fog or rain droplets tend to form around ions or electrons in the air.
A positively charged rod is brought close to a neutral piece of paper, which it attracts, Draw a diagram showing the separation of charge and explain why attraction occurs.
Why does a plastic ruler that has been rubbed with a cloth have the ability to pick up small pieces of paper? Why is this difficult to do on a humid day?
Contrast the net charge on a conductor to the “free charges” in the conductor.
Figures 16-7 and 16-8 show how a charged rod placed near an uncharged metal object can attract (or repel) electron. There are a great many electrons in the metal, yet only some of them some as shown.
When an electroscope is charged, its two leaves repel each other and remain at an angle. What balances the electric force of repulsion so that the leaves don’t separate further?
The form of Coulomb’s law is very similar to that for Newton’s law of universal gravitation. What are the differences between these two laws? Compare also gravitational mass and electric charge?
We are not normally aware of the gravitational or electric force between two ordinary objects. What is the reason in each case? Give an example where we are aware of each one and why.
Is the electric force a conservative force? Why or why not? (See Chapter 6)
When a charged ruler attracts small pieces of paper, sometimes a piece jumps quickly away after touching the ruler. Explain.
Calculate the magnitude of the force between tow 3.60-C point charges 9.3 cm apart.
How many electrons make up a charge of –30.0μC?
What is the magnitude of the electric force of attraction between an iron nucleus (q = + 26e) and its inner-most electron if the distance between them is 1.5 X 10-12m?
What is the repulsive electrical force between two protons 5.0 X 10-15 m apart from each other in an atomic nucleus?
What is the magnitude of the force a + 25 μC charge exerts on a + 3.0mC charge 35 cm away?
Two charged dust particles exert a force of 3.2 X 10-2N on each other. What will be the force if they are moved so they are only one-eight as far apart?
Two charged spheres are 8.45 cm apart. They are moved, and the force on each of them is found to have been tripled. How far apart are they now?
A person scuffing her feet on a wool rug on a dry Dy accumulates a net charge of – 42μC. How many excess electrons does she get, and by how much does her mass increase?
What is the total charge of all the electrons in 1.0kg of H2O?
Compare the electric force holding the electron in orbit (r = 0.53 X 10-10m) around the proton nucleus of the hydrogen atom, with the gravitational force between the same electron and proton. What is
Two positive point charges are a fixed distance apart. The sum of their charges is Qt. What charge must each have in order to? (a) Maximize the electric force between them, and(a) Minimize it?
Particles of charge + 75 + 48, and 85μC are placed in a line (Fig. 16-49). The center one is 0.35 m from each of the others. Calculate the net force on each charge due to the other two.
Three positive particles of equal charge, + 11.0μC, are located at the corners of an equilateral triangle of side 15.0cm (Fig. 16-50). Calculate the magnitude and direction of the net force on
A charge of 6.00mC is placed at each corner of a square 0.100m on a side. Determine the magnitude and direction of the force on each charge.
Repeat Problem 14 for the case when two of the positive charges, on opposite comers, are replaced by negative charges of the same magnitude (Fig. 16-51)
At each corner of a square of side l there are point charges of magnitude Q, 2Q, 3Q and 4Q (Fig 16-52). Determine the force on?(a) The charge 2Q, and(b) The charge 3Q, due to the other three charges.
Three charged particles are placed at the corners of an equilateral triangle of side 1.20m (Fig. 16-53). The charges are + 4.0μC, - 8.0μC, and 6.0μC. Calculate the magnitude
Two point charges have a total charge of 560 μC. When placed 1.10m apart, the force each exerts on the other is 22.8N and is repulsive. What is the charge on each?
Two charges, Q0 and 3Q0, are a distance l apart. These two charges are free to move but do not because there is a third charge nearby. What must be the charge and placement of the third charge for
A + 4.75μC and a -3.55μC charge are placed 18.5cm apart where can a third charge be placed so that it experiences no net force?
Two small non-conducting spheres have a total charge of 90.0μC. (a) When placed 1.06m apart, the force each exerts on the other is 12.0N and is repulsive. What is the charge on each? (b)
A charge Q is transferred from an initially uncharged plastic ball to an identical ball 12cm away. The force of attraction is then 17mN. How many electrons were transferred from one ball to the other?
The two strands of the helix-shaped DNA molecule are held together by electrostatic forces as shown in Fig. 16-44. Assume that the net average charge (due to electron sharing) indicated on H and N
How close must two electrons be if the electric force between them is equal to the weight of either at the Earth’s surface?
A 3.0-g copper penny has a positive charge of 38μC. What fraction of its electrons has it lost?
A proton (m = 1.67 X 10-27 kg) is suspended at rest in a uniform electric field E. Take into account gravity at the Earth’s surface, and determine E.
Measurements indicate that there is an electric field surrounding the Earth. Its magnitude is about 150N/C at the Earth’s surface and points inward toward the Earth’s center. What is the
(a) Given the local electric field of 150N/C, what is the acceleration experienced by an electron near the surface of the Earth? (b) What about a proton?(c) Calculate the ratio of each acceleration
A water droplet of radius 0.018 mm remains stationary in the air. If the downward-directed electric field of the Earth is 150N/C, how many excess electron charges must the water droplet have?
Estimate the net force between the CO group and the HN group shown in Fig. 16-62 The C and O have charges ± 0.40e, and the H and N have charges ± 0.20e, where e = 1.6 X 10-10C.
In a simple model of the hydrogen atom, the electron revolves in a circular orbit around the proton with a speed of 1.1 X 106m/s. Determine the radius of the electron’s orbit.
Suppose that electrical attraction, rather than gravity, were responsible for holding the Moon in orbit around the Earth. If equal and opposite charges Q were placed on the Earth and the Moon, what
An electron with speed vo = 21.5 x 106 m/s is traveling parallel to an electric field of magnitude E = 11.4 X 103 N/C. (a) How far will the electron travel before it stops? (b) How much time will
A positive point charge Q1 = 2.5 X 10-5 C is fixed at the origin of coordinates, and a negative charge Q2 = – 5.0 X 10-6C is fixed to the x axis at x = + 2.0m. Find the location of the place(s)
A small lead sphere is encased in insulating plastic and suspended vertically from an ideal spring (k = 126N/m) above a table. Fig.16-63 the total mass of the coated sphere is 0.800kg, and its center
A large electroscope is made with leaves that are 78-cm-long wires with tiny 24-g spheres at the ends. When charged, nearly all the charge resides on the spheres. If the wires
Dry air will break down and generate a spark if the electric field exceeds about 3 X 106N/C. How much charge could be packed onto a green pea (diameter 0.75cm) before the pea spontaneously discharges?
Two point charges, Q1 = -6.7μC and Q2 = 1.8μC are located between two oppositely charged parallel plates, as shown in Fig. 16-65. The two charges are separated by a distance of x = 0.34. Assume
A point charge (m = 1.0g) at the end of an insulating string of length 55cm is observed to be in equilibrium in a uniform horizontal electric field of 12,000N/C, when the pendulums
A point charge of mass 0.210kg, and net charge + 0.340μC hangs at rest at the end of an insulating string above a large sheet of charge. The horizontal sheet of uniform charge creates a uniform
What is the total charge of all the electrons in a 15-kg bat of aluminum? What is the net charge of the bad? (Aluminum has 13 electrons per atom and an atomic mass of 27 u.)
Two small, identical conducting spheres A and B are a distance R apart; each carries the same charge Q. (a) What is the force sphere B exerts on sphere A?An identical sphere with zero charge, spheres
Given the two charges shown in Fig. 16-68, at what position (s) x is the electric field zero? Is the field zero at my other points, not on the x axis?
Two point charges + Q and – Q of mass m, are placed on the ends of a mass less rod of length L, which is fixed to a table by a pin through its center. If the apparatus is then subjected to a
Four equal positive point charges, each of charge 8.0μC, are at the corners of a square of side 9.2cm. What charge should be placed at the center of the square so that all charges are at
What are the magnitude and direction of the electric force on a electron in a uniform electric field of strength 2360N/C that points due east?
A proton is released in a uniform electric field, and it experiences an electric force of 3.75 X 10-14 N toward the south. What are the magnitude and direction of the electric field?
A downward force of 8.4N is exerted on a -8.8μC charge. What are the magnitude and direction of the electric field at this point?
What are the magnitude and direction of the electric field 20.0cm directly above an isolated 33.0 X 10-6C charge?
What is the magnitude of the acceleration experienced by an electron in an electric field of 750N/C? How does the direction of the acceleration depend on the direction of the field at that point?
What are the magnitude and direction of the electric field at a point midway between a – 8.0μC and a + 7.0μC charge 8.0cm apart? Assume no other charges are nearby.
Draw, approximately, the electric field lines about two point charges, + Q and -3Q, which are a distance l apart.
What is the electric field strength at a point in space where a proton (m = 1.67 X 10-27kg) experiences an acceleration of 1 million “g’s”?
An electron is released from rest in a uniform electric field and accelerates to the north at a rate of 115m/s2. What are the magnitude and direction of the electric field?
The electric field midway between two equal but opposite point charges is 745 N/C, and the distance between the charges is 16.0cm. What is the magnitude of the charge on each?
Calculate the electric field at the center of a square 52.5cm on side if one corner is occupied by a + 45.0μC charge and the other three are occupied by – 27.0μC charges.
Calculate the electric field at one corner of a square 1.00m on a side if the other three corners are occupied by 2.25 X 10-6 C charges.
Determine the direction and magnitude of the electric field at the point P in Fig. 16-54. The charges are separated by a distance 2a, and point P is a distance x from the midpoint between the two
Two point charges, Q1 = - 25μC and Q2 = + 50μC, are separated by a distance of 12cm. The electric field at the point P (See Fig. 16-55) is zero. How far from Q1 is P?
(a) Determine the electric field E at the origin 0 in Fig. 16-56 due to the two charges at A and B.(b) Repeat, but let the charge at B be reversed in sign.
Use Coulombs law to determine the magnitude and direction of the electric field at points A and B in Fig. 16-57 due to the two positive charges (Q = 7.0μC) shown. Are your results
You are given two unknown point charges, Q1 and Q2. At a point on the line joining them, one-third of the away from Q1 to Q2, the electric field is zero (Fig. 16-58). What is the ratio Q1/Q2?
Determine the direction and magnitude of the electric field at the point P shown in Fig. 16-59. The two charges are separated by a distance of 2a. Point P is on the perpendicular bisector of the line
An electron (mass m = 9.11 X 10-31lg) is accelerated in the uniform field E (E = 1.45 X 104N/C) between two parallel charged plates. The separation of the plates is 1.10cm. The electron is
An electron moving to the right at 1.0% the speed of light enters a uniform electric field parallel to its direction of motion. If the electron is to be brought to rest in the space of 4.0cm, (a)
Explain why the test charges we use when measuring electric fields must be small.
When determining an electric field, must we use a positive test charge, or would negative one do as well? Explain.
Draw the electric field lines surrounding two negative electric charges a distance I apart.
Assume that the two opposite charges in Fig. 16-31a are 12.0 cm apart. Consider the magnitude of the electric field 2.5cm from the positive charge. On which side of this charge-top, bottom, left, or
Consider the electric field at points A, B, and C in Fig. 16-48. First draw an arrow at each point indicating the direction of the net force that a positive test charge would experience if placed at
Why can electric field lines never cross?
Show, using the three rules for field lines given in Section 16-8, that the electric field lines starting or ending on a single point charge must be symmetrically spaced around the charge?
Given two point charges Q and 2Q, a distance l apart, is there a point along the straight line that passes through them where E = 0 when their sings are?(a) Opposite,(b) The same? If yes, state
Consider a small positive test charge located on an electric field line at some point, such as point P in Fig. 16-31a is the direction of the velocity and/or acceleration of the test charge along
Sketch the electric field lines for a uniform line of charge which is infinitely long.
If the electric flux through a closed surface is zero, is the electric field necessarily zero at all points on the surface? Explain. What about the converse: If E = 0 at all points on the surface is
A point charge is surrounded by a spherical Gaussian surface of radius r. If the sphere is replaced by a cube of side r, will ΦE be larger, smaller, or the same? Explain.
You may have heard that one of the safer places to be during a lightning storm is inside a car. Why would this be the case?
The total electric flux from a cubical box 28.0 cm on a side is 1.45 X 103 N m2/C. What charge is enclosed by the box?
A flat circle of radius 18cm is placed in a uniform electric field of magnitude 5.8 X 102N/C. What is the electric flux through the circle when its face is?(a) Perpendicular to the field lines,(b) AT
In Fig. 16-61m two objects O1 and O2, have charges + 1.0μC and -2.0μC, respectively, and a third object, O3, is electrically neutral. (a) What is the electric flux through the surface A1 that
A cube of side l is places in a uniform field E = 6.50 X 103 N/C with edges parallel to the field lines.(a) What is the net flux through the cube?(b) What is the flux though each of its six faces?
The electric field between two square metal plates is 130N/C. The plates are 1.0m on a side and are separated by 3.0 cm. What is the charge on each plate (assume equal and opposite)? Neglect edge
The field just outside 3.50-cm-radius metal ball is 2.75 X 102 N/C and points toward the ball. What charge resides on the ball?
A solid metal sphere of radius 3.00 m carries a total charge of -3.50μC. What is the magnitude of the electric field at a distance from the sphere’s center of? (a) 0.15m, (b) 2.90m, (c)
A point charge Q rests at the center of an uncharged thin spherical conducting shell. (See Fig 16-33). What is the electric field E as a function of r?(a) For r less than the inner radius of the
If two points are at the same potential, does this mean that now work is done is moving a test charge from one point to the other? Does this imply that no force need be exerted? Explain.
If a negative charge is initially at rest in an electric field, will it move toward a region of higher potential or lower potential? What about a positive charge? How does the potential? What about a
State clearly the difference (a) Between electric potential and electric field,(b) Between electric potential and electric potential energy.
An electron is accelerated by a potential difference of, say, 0.20 V. How much greater would its final speed be if it is accelerated with four times as much voltage? Explain.
Showing 2000 - 2100
of 8946
First
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Last