physics

D) radiate outward.

Electric field lines near positive point charges A) circle clockwise. B) circle counter-clockwise. C) radiate inward. D) radiate outward.

B) by induction

How can a negatively charged rod charge an electroscope positively? A) by conduction B) by induction C) by deduction D) It cannot.

D) the electric field on the surface of the conductor is perpendicular to the surface.

If a conductor is in electrostatic equilibrium near an electric charge A) the total charge on the conductor must be zero. B) the force between the conductor and the charge must be zero. C) the total electric field of the conductor must be zero. D) the electric field on the surface of the conductor is perpendicular to the surface.

C) zero for both.

If a solid metal sphere and a hollow metal sphere of equal diameters are each given the same charge, the electric field (E) midway between the center and the surface is A) greater for the solid sphere than for the hollow sphere. B) greater for the hollow sphere than for the solid sphere. C) zero for both. D) equal in magnitude for both, but one is opposite in direction from the other.

A) Yes, they always attract.

Is it possible for a positive and a negative charge to attract each other? A) Yes, they always attract. B) Yes, they will attract if they are close enough. C) Yes, they will attract if one carries a larger charge than the other. D) No, they will never attract.

D) No, they will never attract.

Is it possible for two negative charges to attract each other? A) Yes, they always attract. B) Yes, they will attract if they are close enough. C) Yes, they will attract if one carries a larger charge than the other. D) No, they will never attract.

C) No, a zero electric field cannot exist between the two charges.

Is it possible to have a zero electric field value between a negative and positive charge along the line joining the two charges? A) Yes, if the two charges are equal in magnitude. B) Yes, regardless of the magnitude of the two charges. C) No, a zero electric field cannot exist between the two charges. D) cannot be determined without knowing the separation between the two charges

B) Yes, regardless of the magnitude of the two charges.

Is it possible to have a zero electric field value between two positive charges along the line joining the two charges? A) Yes, if the two charges are equal in magnitude. B) Yes, regardless of the magnitude of the two charges. C) No, a zero electric field cannot exist between the two charges. D) cannot be determined without knowing the separation between the two charges

B) conductors

Materials in which the electrons are bound very loosely to the nuclei and can move about freely within the material are referred to as A) insulators. B) conductors. C) semiconductors. D) superconductors.

A) insulators.

Materials in which the electrons are bound very tightly to the nuclei are referred to as A) insulators. B) conductors. C) semiconductors. D) superconductors

D) 56° above -x axis

Q1 = 6.0 nC is at (0.30 m, 0); Q2 = -1.0 nC is at (0, 0.10 m); Q3 = 5.0 nC is at (0, 0). What is the direction of the net force on the 5.0 nC charge? A) 34° above +x axis B) 34° above -x axis C) 56° above +x axis D) 56° above -x axis

C) 5.4 × 10-6 N

Q1 = 6.0 nC is at (0.30 m, 0); Q2 = -1.0 nC is at (0, 0.10 m); Q3 = 5.0 nC is at (0, 0). What is the magnitude of the net force on the 5.0 nC charge? A) 3.0 × 10-6 N B) 4.5 × 10-6 N C) 5.4 × 10-6 N D) 7.2 × 10-6 N

C) x = 1.5 m

A +3.0-C charge is at the origin and a +9.0-C charge is at x = 4.0 m. Where on the x-axis can a third charge be placed so the net force on it is zero? A) x = 0.50 m B) x = 0.60 m C) x = 1.5 m D) x = 2.4 m

D) 25 nC

A 1.0-C charge is 15 m from a second charge, and the force between them is 1.0 N. What is the magnitude of the second charge? A) 25 C B) 1.0 C C) 0.025 C D) 25 nC

D) 4.7 m from the 0 cm mark

A 5.0 μC charge is placed at the 0 cm mark of a meter stick and a -4.0 μC charge is placed at the 50 cm mark. At what point on a line joining the two charges is the electric field zero? A) 1.4 m from the 0 cm mark B) 2.9 m from the 0 cm mark C) 3.3 m from the 0 cm mark D) 4.7 m from the 0 cm mark

D) 1.4 × 106 N/C

A 5.0 μC charge is placed at the 0 cm mark of a meter stick and a -4.0 μC charge is placed at the 50 cm mark. What is the electric field at the 30 cm mark? A) 4.0 × 105 N/C B) 5.0 × 105 N/C C) 9.0 × 105 N/C D) 1.4 × 106 N/C

B) away from the 5.0 C

A 5.0-C charge is 10 m from a small test charge. What is the direction of the electric field? A) toward the 5.0 C B) away from the 5.0 C C) perpendicular to a line joining the charges D) none of the given answers

C) 4.5 × 108 N/C

A 5.0-C charge is 10 m from a small test charge. What is the magnitude of the electric field at the location of the test charge? A) 4.5 × 106 N/C B) 4.5 × 107 N/C C) 4.5 × 108 N/C D) 4.5 × 109 N/C

B) 0.45 N

A 5.0-C charge is 10 m from a small test charge. What is the magnitude of the force experienced by a 1.0 nC charge placed at the location of the test charge? A) 0.045 N B) 0.45 N C) 4.5 N D) 45 N

C) 35 cm

A copper penny has a mass of 3.0 g. A total of 4.0 × 1012 electrons are transferred from one neutral penny to another. If the electrostatic force of attraction between the pennies is equal to the weight of a penny, what is the separation between them? A) 31 cm B) 33 cm C) 35 cm D) 37 cm

B) acquires a negative charge.

A glass rod is rubbed with a piece of silk. During the process the glass rod acquires a positive charge and the silk A) acquires a positive charge also. B) acquires a negative charge. C) remains neutral. D) could either be positively charged or negatively charged. It depends on how hard the rod was rubbed.

A) The first ball is positive, and the second ball is negative.

A large negatively charged object is placed on an insulated table. A neutral metallic ball rolls straight toward the object, but stops before it touches it. A second neutral metallic ball rolls along the path followed by the first ball, strikes the first ball, and stops. The first ball rolls forward, but does not touch the negative object. At no time does either ball touch the negative object. What is the final charge on each ball? A) The first ball is positive, and the second ball is negative. B) The first ball is negative, and the second ball is positive. C) Both balls remain neutral. D) Both balls are positive.

B) negative.

A negatively charged rod is brought near one end of an uncharged metal bar. The end of the metal bar farthest from the charged rod will be charged A) positive. B) negative. C) neutral. D) none of the given answers

D) the same number of protons as electrons.

A neutral atom always has A) more neutrons than protons. B) more protons than electrons. C) the same number of neutrons as protons. D) the same number of protons as electrons.

A) 1.25 × 1013

A piece of plastic has a net charge of +2.00 μC. How many more protons than electrons does this piece of plastic have? A) 1.25 × 1013 B) 1.25 × 1019 C) 2.50 × 1013 D) 2.50 × 1019

A) zero

A point charge of +Q is placed at the center of a square. When a second point charge of -Q is placed at one of the square's corners, it is observed that an electrostatic force of 2.0 N acts on the positive charge at the square's center. Now, identical charges of -Q are placed at the other three corners of the square. What is the magnitude of the net electrostatic force acting on the positive charge at the center of the square? A) zero B) 2.8 N C) 4.0 N D) 8.0 N

B) They move closer together.

A positive object touches a neutral electroscope, and the leaves separate. Then a negative object is brought near the electroscope, but does not touch it. What happens to the leaves? A) They separate further. B) They move closer together. C) They are unaffected. D) cannot be determined without further information

A) diminished to zero.

A positive point charge is enclosed in a hollow metallic sphere that is grounded. As compared to the case without the hollow sphere, the electric field at a point directly above the hollow sphere has A) diminished to zero. B) diminished somewhat. C) increased somewhat. D) not changed.

A) positive charge.

A proton carries a A) positive charge. B) neutral charge. C) negative charge. D) variable charge.

D) There is no electric field in the block's interior.

A solid block of metal in electrostatic equilibrium is placed in a uniform electric field. Give a statement concerning the electric field in the block's interior. A) The interior field points in a direction opposite to the exterior field. B) The interior field points in a direction that is at right angles to the exterior field. C) The interior points in a direction that is parallel to the exterior field. D) There is no electric field in the block's interior.

C) There is a force of attraction between them.

Sphere A carries a net charge and sphere B is neutral. They are placed near each other on an insulated table. Which statement best describes the electrostatic force between them? A) There is no force between them since one is neutral. B) There is a force of repulsion between them. C) There is a force of attraction between them. D) The force is attractive if A is charged positively and repulsive if A is charged negatively.

A cubic block of aluminum rests on a wooden table in a region where a uniform electric field is directed straight upward. What can be said concerning the charge on the block's top surface? A) The top surface is charged positively.

A) The top surface is charged positively.

C) Sphere B is now negatively charged

Sphere A carries a net positive charge, and sphere B is neutral. They are placed near each other on an insulated table. Sphere B is briefly touched with a wire that is grounded. Which statement is correct? A) Sphere B remains neutral. B) Sphere B is now positively charged. C) Sphere B is now negatively charged, D) The charge on sphere B cannot be determined without additional information.

The total flux summed over any closed surface is equal to the net charge enclosed by the surface divided by M sub 0 .

State Gauss's law

The net amount of electric charge produced in any process is zero. or No net electric charge can be created or destroyed.

State the law of conservation of electric charge.

(1) The electric field inside a conductor is zero in the static situation. (2) Any net charge on a conductor distributes itself on the surface. (3) The electric field is always perpendicular to the surface outside of a conductor.

State three properties of conductors in static equilibrium.

B) a negative ion.

An atom has more electrons than protons. The atom is A) a positive ion. B) a negative ion. C) a superconductor. D) impossible.

E) 9.2 nN

An atomic nucleus has a charge of +40e. An electron is 10-9 m from the nucleus. What is the force on the electron? A) 2.9 nN B) 1000 C C) 3.7 nN D) 6.8 nN E) 9.2 nN

B) 5.8 × 10-8 N/C

An atomic nucleus has a charge of +40e. What is the magnitude of the electric field at a distance of 1.0 m from the nucleus? A) 5.6 × 10-8 N/C B) 5.8 × 10-8 N/C C) 6.0 × 10-8 N/C D) 6.2 × 10-8 N/C

D) It becomes zero.

An electron and a proton are separated by a distance of 1.0 m. What happens to the magnitude of the force on the first electron if a second electron is placed next to the proton? A) It doubles. B) It does not change. C) It is reduced to half. D) It becomes zero.

B) It doubles.

An electron and a proton are separated by a distance of 1.0 m. What happens to the magnitude of the force on the proton if a second electron is placed next to the first electron? A) It quadruples. B) It doubles. C) It will not change. D) It goes to zero.

A) It increases to 4 times its original value.

An electron and a proton are separated by a distance of 1.0 m. What happens to the size of the force on the proton if the electron is moved 0.50 m closer to the proton? A) It increases to 4 times its original value. B) It increases to 2 times its original value. C) It decreases to one-half its original value. D) It decreases to one-fourth its original value.

D) 5.1 m

An electron is held up against the force of gravity by the attraction of a fixed proton some distance above it. How far above the electron is the proton? A) 1.5 m B) 2.3 m C) 3.7 m D) 5.1 m

C) becomes positively charged.

An originally neutral electroscope is briefly touched with a positively charged glass rod. The electroscope A) remains neutral. B) becomes negatively charged. C) becomes positively charged. D) could become either positively or negatively charged, depending on the time of contact

B) is negatively charged.

An originally neutral electroscope is grounded briefly while a positively charged glass rod is held near it. After the glass rod is removed, the electroscope A) remains neutral. B) is negatively charged. C) is positively charged. D) could be either positively or negatively charged, depending on how long the contact with ground lasted.

C) is one-half its original value.

At twice the distance from a point charge, the strength of the electric field A) is four times its original value. B) is twice its original value. C) is one-half its original value. D) is one-fourth its original value.

A) 6.25 × 1018.

The charge carried by one electron is e = -1.6 × 10-19 C. The number of electrons necessary to produce a charge of -1.0 C is A) 6.25 × 1018. B) 6.25 × 109. C) 1.6 × 1019. D) none of the given answers

C) 3.7 m

The force between a 30-μC charge and a -90-μC charge is 1.8 N. How far apart are they? A) 1.9 m B) 2.3 m C) 3.7 m D) 4.2 m

B) nucleus consisting of both protons and neutrons, surrounded by a cloud of electrons.

The model of the atom shows a A) neutrally charged nucleus surrounded by both protons and electrons. B) nucleus consisting of both protons and neutrons, surrounded by a cloud of electrons. C) nucleus consisting of both electrons and neutrons, surrounded by a cloud of protons. D) nucleus consisting of both protons and electrons, surrounded by a cloud of neutrons

A) 1.6 N

Three identical charges of 3.0 μC are placed at the vertices of an equilateral triangle which measures 30 cm on a side. What is the magnitude of the electrostatic force which acts on any one of the charges? A) 1.6 N B) 1.8 N C) 2.0 N D) 2.2 N

A) 0.18 N left

Three identical point charges of 2.0 μC are placed on the x-axis. The first charge is at the origin, the second to the right at x = 50 cm, and the third is at the 100 cm mark. What are the magnitude and direction of the electrostatic force which acts on the charge at the origin? A) 0.18 N left B) 0.18 N right C) 0.36 N left D) 0.36 N right

D) 0.189 N

Three point charges are located at the following positions: Q1 = 2.00 μC at x = 1.00 m; Q2 = 3.00 μC at x = 0; Q3 = -5.00 μC at x = -1.00 m. What is the magnitude of the force on the 3.00-μC charge? A) 5.40 × 10-2 N B) 0.135 N C) 8.10 × 10-2 N D) 0.189 N

A) 0.072 N right

Three point charges are placed on the x-axis. A charge of +2.0 μC is placed at the origin, -2.0 μC to the right at x = 50 cm, and +4.0 μC at the 100 cm mark. What are the magnitude and direction of the electrostatic force which acts on the charge at the origin? A) 0.072 N right B) 0.072 N left C) 0.14 N right D) 0.14 N left

C) 20 nC

Two 0.20-g metal spheres are hung from a common point by nonconducting threads which are 30 cm long. Both are given identical charges, and the electrostatic repulsion forces them apart until the angle between the threads is 20°. How much charge was placed on each sphere? A) 10 nC B) 15 nC C) 20 nC D) 25 nC

A) 95 km

Two 1.0-C charges have a force between them of 1.0 N. How far apart are they? A) 95 km B) 9.5 m C) 4.0 m D) 4.0 mm

C) The charges exert forces on each other equal in magnitude and opposite in direction.

Two charged objects are separated by a distance d. The first charge is larger in magnitude than the second charge. A) The first charge exerts a larger force on the second charge. B) The second charge exerts a larger force on the first charge. C) The charges exert forces on each other equal in magnitude and opposite in direction. D) The charges exert forces on each other equal in magnitude and pointing in the same direction.

A) quadruples.

Two charged objects attract each other with a certain force. If the charges on both objects are doubled with no change in separation, the force between them A) quadruples. B) doubles. C) halves. D) increases, but we can't say how much without knowing the distance between them.

D) 96F.

Two charged objects attract each other with a force F. What happens to the force between them if one charge is doubled, the other charge is tripled, and the separation distance between their centers is reduced to one-fourth its original value? The force is now equal to A) 16F. B) 24F. C) (3/8)F. D) 96F.

D) 9F

Two charges are separated by a distance d and exert mutual attractive forces of F on each other. If the charges are separated by a distance of d/3, what are the new mutual forces? A) F/9 B) F/3 C) 3F D) 9F

A) zero

Two point charges each have a value of 3.0 C and are separated by a distance of 4.0 m. What is the electric field at a point midway between the two charges? A) zero B) 9.0 × 107 N/C C) 18 × 107 N/C D) 4.5 × 107 N/C

D) 1/16 N

Two point charges, initially 2.0 cm apart, experience a 1.0-N force. If they are moved to a new separation of 8.0 cm, what is the electric force between them? A) 4.0 N B) 16 N C) 1/4 N D) 1/16 N

C) 320 N

Two point charges, separated by 1.5 cm, have charge values of 2.0 and -4.0 μC, respectively. What is the magnitude of the electric force between them? A) 400 N B) 360 N C) 320 N D) 160 N

C) 200 N/C away from the charge

What are the magnitude and direction of the electric field at a distance of 1.50 m from a 50.0-nC charge? A) 20 N/C away from the charge B) 20 N/C toward the charge C) 200 N/C away from the charge D) 200 N/C toward the charge

D) N∙m2/C2

What are the units of the Coulomb constant k, which appears in Coulomb's law? A) N∙m/C B) N/C C) N2∙m/C2 D) N∙m2/C2

C) 9.6 × 107 C

What is the charge on 1 kg of protons? A) 1.0 C B) 1000 C C) 9.6 × 107 C D) 6.0 × 1026 C

D) No.

Can electric field lines intersect in free space? A) Yes, but only at the midpoint between two equal like charges. B) Yes, but only at the midpoint between a positive and a negative charge. C) Yes, but only at the centroid of an equilateral triangle with like charges at each corner. D) No.

B) 6.8a

Charge +2q is placed at the origin and charge -q is placed at x = 2a. Where can a third positive charge +q be placed so that the force on it is zero? A) 3.4a B) 6.8a C) 8.6a D) 9.3a

D) all of the given answers

Charge is A) quantized. B) conserved. C) invariant. D) all of the given answers

B) 1.0 m from the +Q charge

Consider point charges of +Q and +4Q, which are separated by 3.0 m. At what point, on a line between the two charges, would it be possible to place a charge of -Q such that the electrostatic force acting on it would be zero? A) There is no such point possible. B) 1.0 m from the +Q charge C) 1.0 m from the +4Q charge D) 0.60 m from the +Q charge

C) electric charge

Which of the following is not a vector? A) electric force B) electric field C) electric charge D) electric line of force