Question 1

A neutral metal ball is suspended by a string.A positively charged insulating rod is placed near the ball, which is observed to be attracted to the rod.This is because:

Accepted Answer

A) the ball becomes positively charged by induction 
B) the ball becomes negatively charged by induction 
C) the number of electrons in the ball is more than the number in the rod 
D) the string is not a perfect insulator 
E) there is a rearrangement of the electrons in the ball 
A) the ball becomes positively charged by induction 
B) the ball becomes negatively charged by induction 
C) the number of electrons in the ball is more than the number in the rod 
D) the string is not a perfect insulator 
E) there is a rearrangement of the electrons in the ball

Question 2

A charge Q is spread uniformly along the circumference of a circle of radius R.A point particle with charge q is placed at the center of this circle.The total force exerted on the particle q can be calculated by Coulomb's law:

Accepted Answer

A) if you use R for the distance 
B) if you use 2R for the distance 
C) if you use 2 $\pi$R for the distance 
D) and the result of the calculation is zero 
E) none of the above 
A) if you use R for the distance 
B) if you use 2R for the distance 
C) if you use 2 $\pi$R for the distance 
D) and the result of the calculation is zero 
E) none of the above

Question 3

Two protons (p1 and p2)and an electron (e)lie on a straight line, as shown.The directions of the force of p1 on e, the force of p2 on e, and the total force on e, respectively, are:

Accepted Answer

A) "$\rightarrow$, $\leftarrow$, $\rightarrow$" 
B) "$\leftarrow$,$\rightarrow$, $\rightarrow$" 
C) "$\rightarrow$, $\leftarrow$, $\leftarrow$" 
D) "$\leftarrow$, $\rightarrow$, $\rightarrow$" 
E) "$\leftarrow$, $\leftarrow$, $\leftarrow$" 
A) "$\rightarrow$, $\leftarrow$, $\rightarrow$" 
B) "$\leftarrow$,$\rightarrow$, $\rightarrow$" 
C) "$\rightarrow$, $\leftarrow$, $\leftarrow$" 
D) "$\leftarrow$, $\rightarrow$, $\rightarrow$" 
E) "$\leftarrow$, $\leftarrow$, $\leftarrow$"

Question 4

A positively charged metal sphere A is brought into contact with an uncharged metal sphere B.As a result:

Accepted Answer

A) both spheres are positively charged 
B) A is positively charged and B is neutral 
C) A is positively charged and B is negatively charged 
D) A is neutral and B is positively charged 
E) A is neutral and B is negatively charged 
A) both spheres are positively charged 
B) A is positively charged and B is neutral 
C) A is positively charged and B is negatively charged 
D) A is neutral and B is positively charged 
E) A is neutral and B is negatively charged

Question 5

Two electrons (e1 and e2)and a proton (p)lie on a straight line, as shown.The directions of the force of e2 on e1, the force of p on e1, and the total force on e1, respectively, are:

Accepted Answer

A) "$\rightarrow$, $\leftarrow$, $\rightarrow$" 
B) "$\leftarrow$, $\rightarrow$, $\rightarrow$" 
C) "$\rightarrow$, $\leftarrow$, $\leftarrow$" 
D) "$\leftarrow$,$\rightarrow$, $\leftarrow$" 
E) "$\leftarrow$, $\leftarrow$, $\leftarrow$" 
A) "$\rightarrow$, $\leftarrow$, $\rightarrow$" 
B) "$\leftarrow$, $\rightarrow$, $\rightarrow$" 
C) "$\rightarrow$, $\leftarrow$, $\leftarrow$" 
D) "$\leftarrow$,$\rightarrow$, $\leftarrow$" 
E) "$\leftarrow$, $\leftarrow$, $\leftarrow$"

Question 6

To what types of electrically charged objects does Coulomb's law apply?

Accepted Answer

A) only pointlike particles 
B) any symmetric objects 
C) it applies to all such objects 
D) only pointlike particles and objects that can be treated as particles 
E) it applies to all such objects as long as they are not moving 
A) only pointlike particles 
B) any symmetric objects 
C) it applies to all such objects 
D) only pointlike particles and objects that can be treated as particles 
E) it applies to all such objects as long as they are not moving

Question 7

A negatively charged rubber rod is brought near the knob of a positively charged electroscope.The result is that:

Accepted Answer

A) electroscope leaves will move farther apart 
B) the rod will lose its charge 
C) electroscope leaves will tend to collapse 
D) electroscope will become discharged 
E) nothing noticeable will happen 
A) electroscope leaves will move farther apart 
B) the rod will lose its charge 
C) electroscope leaves will tend to collapse 
D) electroscope will become discharged 
E) nothing noticeable will happen

Question 8

Two particles have charges Q and -Q (equal magnitude and opposite sign).For a net force of zero to be exerted on a third charge it must be placed:

Accepted Answer

A) midway between Q and -Q 
B) on the perpendicular bisector of the line joining Q and -Q, but not on that line itself 
C) on the line joining Q and -Q, to the side of Q opposite -Q 
D) on the line joining Q and -Q, to the side of -Q opposite Q 
E) at none of these places (there is no place) 
A) midway between Q and -Q 
B) on the perpendicular bisector of the line joining Q and -Q, but not on that line itself 
C) on the line joining Q and -Q, to the side of Q opposite -Q 
D) on the line joining Q and -Q, to the side of -Q opposite Q 
E) at none of these places (there is no place)

Question 9

A particle with charge 2$\mu$C is placed at the origin.An identical particle, with the same charge, is placed 2 m from the origin on the x axis, and a third identical particle, with the same charge, is placed 2 m from the origin on the y axis.The magnitude of the force on the particle at the origin is:

Accepted Answer

A) 9.0 * 10-3 N 
B) 6.4 * 10-3 N 
C) 1.3 * 10-2 N 
D) 1.8 * 10-2 N 
E) 3.6 * 10-2 N 
A) 9.0 * 10-3 N 
B) 6.4 * 10-3 N 
C) 1.3 * 10-2 N 
D) 1.8 * 10-2 N 
E) 3.6 * 10-2 N

Question 10

The magnitude of the total negative charge on the electrons in 1 kg of helium (atomic number 2, atomic mass 4)is:

Accepted Answer

A) 48 C 
B) 2.4 * 107 C 
C) 4.8 * 107 C 
D) 9.6 * 107 C 
E) 1.9 * 108 C 
A) 48 C 
B) 2.4 * 107 C 
C) 4.8 * 107 C 
D) 9.6 * 107 C 
E) 1.9 * 108 C

Question 11

Two uncharged metal spheres, L and M, are in contact.A negatively charged rod is brought close to L, but not touching it, as shown.The two spheres are slightly separated and the rod is then withdrawn.As a result:

Accepted Answer

A) both spheres are neutral 
B) both spheres are positive 
C) both spheres are negative 
D) L is negative and M is positive 
E) L is positive and M is negative 
A) both spheres are neutral 
B) both spheres are positive 
C) both spheres are negative 
D) L is negative and M is positive 
E) L is positive and M is negative

Question 12

The units of 1/4 $\pi$$\varepsilon$0 are:

Accepted Answer

A) N2/C2 
B) N.m/C 
C) N2.m2/C2  
D) N.m2/C2 
E) m2/C2 
A) N2/C2 
B) N.m/C 
C) N2.m2/C2  
D) N.m2/C2 
E) m2/C2

Question 13

An electroscope is charged by induction using a glass rod that has been made positive by rubbing it with silk.The electroscope leaves:

Accepted Answer

A) gain electrons 
B) gain protons 
C) lose electrons 
D) lose protons 
E) gain an equal number of protons and electrons 
A) gain electrons 
B) gain protons 
C) lose electrons 
D) lose protons 
E) gain an equal number of protons and electrons

Question 14

The diagram shows two pairs of highly charged plastic cubes.Cubes 1 and 2 attract each and cubes 1 and 3 repel each other.   Which of the following illustrates the forces of cube 2 on 3 and cube 3 on 2?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 15

The charge on a glass rod which has been rubbed with silk is called positive:

Accepted Answer

A) by arbitrary convention 
B) so that the proton charge will be positive 
C) to conform to the conventions adopted for G and m in Newton's law of gravitation 
D) because like charges repel 
E) because glass is an insulator 
A) by arbitrary convention 
B) so that the proton charge will be positive 
C) to conform to the conventions adopted for G and m in Newton's law of gravitation 
D) because like charges repel 
E) because glass is an insulator

Question 16

The diagram shows a pair of highly charged plastic cubes that attract each other.   Cube 3 is a conductor and is uncharged.Which of the following illustrates the forces between cubes1 and 3 and between cubes 2 and 3?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 17

A 5.0-C charge is 10 m from a -2.0-C charge.The electrostatic force is on the positive charge is:

Accepted Answer

A) 9.0 * 108 N toward the negative charge 
B) 9.0 *108 N away from the negative charge 
C) 9.0 * 109 N toward the negative charge 
D) 9.0 * 109 N away from the negative charge 
E) none of these 
A) 9.0 * 108 N toward the negative charge 
B) 9.0 *108 N away from the negative charge 
C) 9.0 * 109 N toward the negative charge 
D) 9.0 * 109 N away from the negative charge 
E) none of these

Question 18

Two particles A and B have identical charge Q.For a net force of zero to be exerted on a third charged particle it must be placed:

Accepted Answer

A) midway between A and B 
B) on the perpendicular bisector of the line joining A and B but away from the line 
C) on the line joining A and B, not between the particles 
D) on the line joining A and B, closer to one of them than the other 
E) at none of these places (there is no place) 
A) midway between A and B 
B) on the perpendicular bisector of the line joining A and B but away from the line 
C) on the line joining A and B, not between the particles 
D) on the line joining A and B, closer to one of them than the other 
E) at none of these places (there is no place)

Question 19

Two identical charges, 2.0 m apart, exert forces of magnitude 4.0 N on each other.The value of either charge is:

Accepted Answer

A) 1.8*10-9 C 
B) 2.1 *10-5 C 
C) 4.2 * 10-5 C 
D) 1.9 * 105 C 
E) 3.8 *105 C 
A) 1.8*10-9 C 
B) 2.1 *10-5 C 
C) 4.2 * 10-5 C 
D) 1.9 * 105 C 
E) 3.8 *105 C

Question 20

In the Rutherford model of the hydrogen atom, a proton (mass M, charge Q)is the nucleus and an electron (mass m, charge q)moves around the proton in a circle of radius r.Let k denote the Coulomb force constant (1/4 $\pi$$\varepsilon$0)and G the universal gravitational constant.The ratio of the electrostatic force to the gravitational force between electron and proton is:

Accepted Answer

A) kQq/GMmr2 
B) GQq/kMm 
C) kMm/GQq 
D) GMm/kQq 
E) kQq/GMm 
A) kQq/GMmr2 
B) GQq/kMm 
C) kMm/GQq 
D) GMm/kQq 
E) kQq/GMm

Exam 21: Electric Charge

A neutral metal ball is suspended by a string.A positively charged insulating rod is placed near the ball, which is observed to be attracted to the rod.This is because:

A charge Q is spread uniformly along the circumference of a circle of radius R.A point particle with charge q is placed at the center of this circle.The total force exerted on the particle q can be calculated by Coulomb's law:

Two protons (p1 and p2)and an electron (e)lie on a straight line, as shown.The directions of the force of p1 on e, the force of p2 on e, and the total force on e, respectively, are:

A positively charged metal sphere A is brought into contact with an uncharged metal sphere B.As a result:

Two electrons (e1 and e2)and a proton (p)lie on a straight line, as shown.The directions of the force of e2 on e1, the force of p on e1, and the total force on e1, respectively, are:

To what types of electrically charged objects does Coulomb's law apply?

A negatively charged rubber rod is brought near the knob of a positively charged electroscope.The result is that:

Two particles have charges Q and -Q (equal magnitude and opposite sign).For a net force of zero to be exerted on a third charge it must be placed:

The magnitude of the total negative charge on the electrons in 1 kg of helium (atomic number 2, atomic mass 4)is:

Two uncharged metal spheres, L and M, are in contact.A negatively charged rod is brought close to L, but not touching it, as shown.The two spheres are slightly separated and the rod is then withdrawn.As a result:

The units of 1/4 π\piπε\varepsilonε 0 are:

An electroscope is charged by induction using a glass rod that has been made positive by rubbing it with silk.The electroscope leaves:

The diagram shows two pairs of highly charged plastic cubes.Cubes 1 and 2 attract each and cubes 1 and 3 repel each other. Which of the following illustrates the forces of cube 2 on 3 and cube 3 on 2?

The charge on a glass rod which has been rubbed with silk is called positive:

The diagram shows a pair of highly charged plastic cubes that attract each other. Cube 3 is a conductor and is uncharged.Which of the following illustrates the forces between cubes1 and 3 and between cubes 2 and 3?

A 5.0-C charge is 10 m from a -2.0-C charge.The electrostatic force is on the positive charge is:

Two particles A and B have identical charge Q.For a net force of zero to be exerted on a third charged particle it must be placed:

Two identical charges, 2.0 m apart, exert forces of magnitude 4.0 N on each other.The value of either charge is:

Measurement

Motion Along a Straight Line

Vector

Motion in Two and Three Dimensions

Force and Motion I

Force and Motion II

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

Gravitation

Fluids

Oscillations

Waves I

Waves II

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Electric Fields

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Electromagnetic Waves

Images

Interference

Diffraction

Relativity

Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Nuclear Physics

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

Two protons (p₁ and p₂)and an electron (e)lie on a straight line, as shown.The directions of the force of p₁ on e, the force of p₂ on e, and the total force on e, respectively, are:

Two electrons (e₁ and e₂)and a proton (p)lie on a straight line, as shown.The directions of the force of e₂ on e₁, the force of p on e₁, and the total force on e₁, respectively, are:

The units of 1/4 $\pi$ $\varepsilon$ ₀ are: