EP2 Final study cards

PE3 15. A loop of current-carrying wire has a magnetic dipole moment of 5.0 ×10^−4 A ·m2. If the dipole moment makes an angle of 57 degrees with a magnetic field of 0.35 T, what is its potential energy? A) -9.5 x 10^-5 J B) -1.5 x 10^-4 J C) -1.8 x 10^-4 J D) 1.5 x 10^-4 J E) 9.5 x10 ^-5 J

A) -9.5 x 10 ^-5 J

PE1 12. A very long wire carries a uniform linear charge density of 7.0 nC/m. What is the magnitude of the electric field 16.0 m from the center of the wire at a point on the wire's perpendicular bisector? A) 7.8 N/C B) 3.9 N/C C) 0.49 N/C D) 0.031 N/C

A) 7.9 N/C

PE2 8. The electric potential in a region of space is given by V = −7.5x^2 + 3x. What is the electric field in this region? A) E = (15x-3)i B) E = (-15x+3)i C) E = (-2.5x -1.5x^2)i D) E = (2.5x^3 - 1.5x^2)i E) E = 0

A) E = (15x-3)i

The specific magnetic behavior of ferromagnetic materials is due to(29.24) A. the domain structure. B. the orbit of the electron. C. the spin of the electron.

A. the domain structure.

The charge of sphere 2 is twice that of sphere 1. Which vector below shows the force of 2 on 1?(22.4) A B C D E

B

PE2 7. During a lightning discharge, 30 C of charge move through a potential difference of 1.0 ×10^8 V in 2.0 ×10^−2 s. The energy released by this lightning bolt is: A) 1.5 x 10^11 J B) 3x10^9 J C) 6x10^7 J D) 3.3x10^6 J E)6.7 x10^4 J

B) 3x10^9 J

PE3 8. A cyclotron operates with a given magnetic field and at a given frequency. If R denotes the radius of the final orbit, the final particle energy is proportional to: A) 1/R B) R C) R^2 D) R^3 E) R^-2

C) R^2

What is the direction of the electric field at the dot?(23.2) A B C D None of the above

D

PE2 13. Two identical capacitors can be connected in series or in parallel. The equivalent capacitance of the series connection is ________________ the equivalent capacitance of parallel connection. A) twice B) four times C) half D) one-fourth E) the same as

D) one-fourth

PE1 10. 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) the ball becomes positively charged by induction B) the string is not a perfect insulator C) the ball becomes negatively charged by induction D) there is a rearrangement of the electrons in the ball

D) there is a rearrangement of the electrons in the ball

A cylindrical Gaussian surface surrounds an infinite line of charge. The flux Φe through the two flat ends of the cylinder is(24.6) A. 2 ×rLE. B. It will require an integration to find out. C. 2 × 2π rE. D. 0. E. 2 × πr2 E.

D. 0.

PE1 7. Two point charges are arranged as shown in figure 1.3. In which region could a third charge of be placed so that the net electrostatic force on it is zero? A) I only B) II only C) I and II only D) III only E) I and III only

A) I only

PE3 7. A loop of wire carrying a current of 2.0 A is in the shape of a right triangle with two equal sides, each 15 cm long. A 0.7 T uniform magnetic field is parallel to the hypotenuse. The total magnetic force on the two equal sides has a magnitude of (Hint: what's the net force on any loop of current in a uniform magnetic field?): A) Zero B) 0.21 N C) 0.30 N D) 0.41 N E) 0.51 N

A) Zero

PE3 13. A long straight cylindrical wire carries current i uniformly distributed over its cross section. The magnitude of the magnetic field is greatest: A) at the surface of the wire B) halfway between the center and the surface of the wire C) everywhere inside the wire, where the field is uniform D) at the center of the wire

A) at the surface of the wire

PE3 11. For a charged particle, a uniform magnetic field can be used to change A) only the direction of the particle's velocity B) only the magnitude of the particle's velocity C) both the magnitude and direction of the particle's velocity D) neither the magnitude nor the direction of the particle's velocity

A) only the direction of the particle's velocity

The current through a wire is measured as the potential difference ΔΔ V is varied. What is the wire's resistance?(27.7) A. 0.02 Ω. B. Some other value. C. 100 Ω. D. 0.01 Ω. E. 50 Ω.

A. 0.02 Ω.

Wire 2 is twice the length and twice the diameter of wire 1. What is the ratio R2R2 / R1R1 of their resistances?(27.5) A. 1/2. B. 1/4. C. 1. D. 4. E. 2.

A. 1/2.

What is the shape of the trajectory that a charged particle follows in a uniform magnetic field?(29.6) A. A helix B. A parabola C. A circle D. An ellipse E. A hyperbola

A. A helix

A positive and a negative charge are released from rest in vacuum. They move toward each other. As they do:(25.2) A. A negative potential energy becomes more negative. B. A negative potential energy becomes less negative. C. A positive potential energy becomes a negative potential energy. D. A positive potential energy becomes more positive. E. A positive potential energy becomes less positive.

A. A negative potential energy becomes more negative.

The magnetic field of a point charge is given by(29.3) A. Biot-Savart's law. B. Faraday's law. C. Gauss's law D. Ampère's law. E. Einstein's law.

A. Biot-Savart's law.

What is the SI unit of charge?(22.1) A. Coulomb B. Faraday C. Ampere D. Ohm E. Volt

A. Coulomb

What is the amount of electric field passing through a surface called?(24.1) A. Electric flux B. Gauss's law C. Electricity D. Charge surface density E. None of the above

A. Electric flux

What is the electron drift speed in a typical current-carrying wire?(27.1) A. Extremely slow (≈10−4m/s). B. Moderate ( ≈1m/s). C. Very fast (≈104m/s). D. Could be extremely slow, moderate, or very fast E. Unknown, since no numerical values were provided

A. Extremely slow (≈10−4m/s).

A long, straight wire extends into and out of the screen. The current in the wire is(29.5) A. Out of the screen. B. Into the screen. C. There is no current in the wire. D. There is not enough information to tell the direction.

A. Out of the screen.

All other things being equal, current will be larger in a wire that has a larger value of(27.4) A. conductivity. B. resistivity. C. the coefficient of current D. net charge. E. potential.

A. conductivity.

The electric field(26.1) A. is always perpendicular to an equipotential surface. B. is always tangent to an equipotential surface. C. always bisects an equipotential surface. D. makes an angle to an equipotential surface that depends on the amount of charge.

A. is always perpendicular to an equipotential surface.

The magnetic force on a charged particle in a magnetic field is zero if ____.(29.23) Select all that apply. A. the charged particle is at rest B. the charged particle is moving C. the charged particle moves perpendicular to the magnetic field D. the charged particle moves parallel to the magnetic field E. The magnetic force on a charged particle is never zero.

A. the charged particle is at rest D. the charged particle moves parallel to the magnetic field

Which is the direction of the net force on the charge at the lower left?(22.5) A B C D E

B

PE2 10. Three point charges of −2.00 μC, 4.00 μC, and 2.00 μC are placed along the x-axis as shown in figure 2.2. What is the change in the electric potential energy of the system if a −2.00 μC is brought in from far away and placed at point P? A) 18.0 mJ B) -18.0 mJ C) 24.4 mJ D) -24 mJ E) Cannot be determined since no reference for the potential energy is provided.

B) -18.0 mJ

PE1 1. Which of the Following is an impossible value of charge A) 1.6 C B) 1.6 e C) 1 C D) 1 e

B) 1.6 e

PE2 15. A wire with a length of 150 m and a radius of 0.15 mm carries a current with a uniform current density of 2.8 ×10^7 A/m^2. The current is: A) .63A B) 2A C) 5.9A D) 300A E) 26000A

B) 2A

PE2 5. A cylindrical wire has a resistance R and resistivity ρ. If its length and diameter are both cut in half, what will be its resistance? A) R B) 2R C) R/2 D) 4R E) R/4

B) 2R

PE2 9. For the electric potential V= 1.5x^2 -2.7x, equipotential surfaces A) are planes containing the x-axis B) are planes parallel to the yz axis C) are concentric spheres centered at the origin D) are concentric cylinders with the x axis as the cylinder axis E) cannot be determined from information provided

B) are planes parallel to the yz plane

PE2 6. An electron is moved from point i to point f, in the direction of a uniform electric field E seen in figure 2.1 .During this motion: A) the work done by the field is positive and the potential energy of the electron increases. B) the work done by the field is negative and the potential energy of the electron increases. C) the work done by the field is positive and the potential energy of the electron decreases. D) the work done by the field is negative and the potential energy of the electron decreases. E) the work done by the field is positive and the potential energy of the electron does not change.

B) the work done by the field is negative and the potential energy of the electron increases.

PE3 3. An emf source is defined in terms of: A) the force it exerts on charges B) the work it does on charges C) the electric field it generates D) the current it generates E) the charge it emits

B) the work it does on charges

This is a graph of the x-component of the electric field along the x-axis. The potential is zero at the origin. What is the potential at x = 1 m?(26.2) A. 0 V B. -1000 V C. -2000 V D. 2000 V E. 1000 V

B. -1000 V

The electric flux through the shaded surface is(24.2) A. 0. B. 400 N m2/C. C. 200 N m/C. D. Flux isn't defined for an open surface.

B. 400 N m2/C.

At which point is the electric field stronger?(26.3) A. There's not enough information to tell. B. At xA. C. The field is the same strength at both. D. At xB.

B. At xA.

For charged particles, what is the quantity q/m called?(23.6) A. Linear charge density B. Charge-to-mass ratio C. Charged mass density D. Massive electric dipole E. Quadrupole moment

B. Charge-to-mass ratio

What is the SI unit of capacitance?(26.5) A. Capaciton B. Farad C. Hertz D. Henry E. Exciton

B. Farad

Two protons, A and B, are in an electric field. Which proton has the larger acceleration? Neglect interactions between the protons.(23.3) A. both have the same acceleration B. Proton A C. Proton B

B. Proton A

If released from rest, the current loop will(29.8) A. Do something not listed here. B. Rotate counterclockwise. C. Rotate clockwise. D. Move downward. E. Move upward.

B. Rotate counterclockwise.

The worked examples of charged-particle motion are relevant to.(23.7) A. a transistor. B. a cathode-ray tube. C. magnetic resonance imaging D. cosmic rays. E. lasers.

B. a cathode-ray tube.

The electric potential inside a capacitor.(25.5) A. is constant. B. increases linearly from the negative to the positive plate. C. decreases linearly from the negative to the positive plate. D. decreases inversely with distance from the negative plate. E. decreases inversely with the square of the distance from the negative plate.

B. increases linearly from the negative to the positive plate.

The electric field inside a conductor in electrostatic equilibrium is(24.7) A. uniform. B. zero. C. radial. D. symmetric.

B. zero.

The figure shows a wire that is connected to a power supply and suspended between the poles of a magnet. When the switch is closed, the wire deflects in the direction shown. Which of the dashed boxes A-D represents the position of the north magnetic pole?(29.21) A B C D

C

PE3 4. A battery with 24 V emf is connected to a 6.0-Ω resistor. As a result, a 3.0-A current flows through the resistor. The rate at which energy is being dissipated in the battery is: A) 3 W B) 6 W C) 18 W D) 54 W E) 72 W

C) 18 W

PE3 2. All the resistors shown in the figure 3.1 are 10 Ω. What is the effective resistance in the circuit? A) 40 Ω B) 30 Ω C) 25 Ω D) 20 Ω E) 10 Ω

C) 25 Ω

PE3 5. A 120-V power line is protected by a 16-A fuse. What is the maximum number of 120 V, 500 W light bulbs that can be operated at full brightness from this line? A) 1 B) 2 C) 3 D) 4 E) 5

C) 3

PE1 13. A thin, circular disk of radius 30.0 cm is oriented in the yz-plane with its center at the origin. The disk carries a total charge of +3.00 μC distributed uniformly over its surface. What is the magnitude of the electric field due to the disk at the point x = 15.0 cm along the x-axis? A) 9.95 x 10^5 N/C B) 4.98 x 10^5 N/C C) 3.31 x 10^5 N/C D) 2.49 x 10^5 N/C E) 1.99 x 10^5 N/C

C) 3.31 x 10^5 N/C

PE3 9. Two parallel wires, 4 cm apart, carry currents of 2 A and 4 A respectively, in the same direction. The force per unit length of one wire on the other is: A) 1 x 10^-3 N/m, repulsive. B) 1 x 10^-3 N/m, attractive C) 4 x 10 ^-5 N/m, attractive D)4 x 10^-5 N/m, repulsive E) none of the above

C) 4 x 10^-5 N/m, attractive

PE1 2. A small sphere B has a charge of +Q. Another identical sphere A has a charge of −2Q The magnitude of the electric force on B due to A is F. The magnitude of the electric force on A due to B is? A) -2F B) 2F C) F D) -F E) F/2

C) F

PE1 15. Two very large parallel sheets a distance d apart have their centers directly opposite each other. The sheets carry equal but opposite uniform surface charge densities. A point charge that i is placed near the middle of the sheets a distance d/2 from each of them feels an electrical force F due to the sheets. If this charge is now moved closer to one of the sheets so that it is a distance d/4 from that sheet, what force will feel? A) 4F B) 2F C) F D) F/2 E) F/4

C) F

PE2 12. A battery is used to charge a parallel combination of two identical capacitors. If the potential difference across the battery terminals is V and the total charge Q flows through the battery during the charging process then the charge on the positive plate of each capacitor and the potential difference across each capacitor are: A) Q/2 and V/2, respectively B) Q and V, respectively C) Q/2 and V, respectively D) Q and V/2 respectively E) 2Q and 2V, respectively

C) Q/2 and V, respectively

PE1 11. An electron is initially moving to the right when it enters a uniform electric field directed upwards. Which trajectory shown in figure 1.5 will the electron follow? A) X B) Y C) Z D) W E) None of the above

C) Z

PE1 9. The electric field lines due to two particles, with charges of q1 and q2, are are shown in the figure 1.4. We conclude that: A) q1 must be positive, q2 must be negative and |q1|>|q2| B) q1 must be positive, q2 must be negative and |q1|<|q2| C) q1 must be negative, q2 must be positive and |q1|>|q2| D) q1 must be negative, q2 must be positive and |q1|<|q2| E) none of the other conclusions is justified by the figure

C) q1 must be negative, q2 must be positive and |q1|>|q2|

PE2 14. Current in a metallic conductor is normally due to: A) the collective motion of all electrons in the conductor B) the thermal motion of the conduction electrons C)the drift motion of the conduction electrons due to electric fields D) the drift motion of both electrons and positrons E) the drift motion of both electrons and protons

C) the drift motion of the conduction electrons due to electric fields

PE1 5. A metal plate is connected to ground through a switch, as shown in the figure 1.2 . The switch is initially closed. A charge +Q is brought close to the plate without touching it, and then the switch is opened to break the connection to ground. After the switch is opened, the charge +Q is removed. What is the charge on the plate then? A) The plate is uncharged B) The plate is positively charged C) The plate is negatively charged D) The plate could be positively of negatively charged; depending on the charge it had before +Q was brought near it. E) The plate could be positively or negatively charged; depending on which metal it is.

C) the plate is negatively charged

PE3 1. A wire with a length of 150 m and a radius of 0.15 mm carries a current with a uniform current density of 2.8 ×107 A/m2. The current is: A)The current in 1 is twice that in 2 B) The current in 1 is half that in 2 C) the potential difference across 1 is twice that across 2 D) the potential difference across 1 is half that across 2. E)none of the above are true

C) the potential difference across 1 is twice that across 2

The equivalent capacitance is(26.6) A. 3 μF B. 2 μF C. 9 μF D. 1 μF E. 6 μF

C. 9 μF

What device provides a practical way to produce a uniform electric field?(23.5) A. A long, thin resistor B. A Faraday cage C. A parallel-plate capacitor D. A toroidal inductor E. An electric field uniformizer

C. A parallel-plate capacitor

What quantity is represented by the symbol J?(27.2) A. Resistivity B. Conductivity C. Current density D. Complex impedance E. Johnston's constant

C. Current density

Currents circulate in a piece of metal that is pulled through a magnetic field. What are these currents called?(30.2) A. Displacement currents B. Faraday's currents C. Eddy currents D. This topic is not covered in this chapter

C. Eddy currents

What property of a real battery makes its potential difference slightly different than that of an ideal battery?(28.2) A. Short circuit B. Chemical potential C. Internal resistance D. Effective capacitance E. Inductive constant

C. Internal resistance

The equation I = Δ V/R is called(27.6) A. Ampère's law. B. Faraday's law. C. Ohm's law. D. Weber's law.

C. Ohm's law.

What is the SI unit for the strength of the magnetic field?(29.2) A. Gauss B. Henry C. Tesla D. Becquerel E. Bohr magneton

C. Tesla

How many laws are named after Kirchhoff?(28.1) A. None B. One C. Two D. Three E. Four

C. Two

New units of the electric field were introduced in this chapter. What are they?.(25.4) A. V/C B. N/C C. V/m D. J/m2 E. Ω/m F. J/C

C. V/m

The magnetic field of a solenoid is analogous to the electric field of a ____.(29.22) A. charged wire B. charged disk C. charged parallel-plate capacitor D. dipole E. battery

C. charged parallel-plate capacitor

What quantity is represented by the symbol E?(26.4) A. Electronic potential B. Excitation potential C. emf D. Electric stopping power E. Exosphericity

C. emf

Gauss's law is useful for calculating electric fields that are(24.3) A. due to point charges. B. uniform. C. symmetric. D. due to continuous charges.

C. symmetric.

If a negatively charged rod is held near a neutral metal ball, the ball is attracted to the rod. This happens because(22.2) A. of magnetic effects. B. the ball tries to pull the rod's electrons over to it. C. the rod polarizes the metal. D. the rod and the ball have opposite charges.

C. the rod polarizes the metal.

PE3 6. A certain capacitor, in series with a resistor, is being charged. At the end of 10 ms its charge is half the final value. The time constant for the process is about: A) 5.0 ms B) 6.9 ms C) 10 ms D) 14 ms E) 20 ms

D) 14 ms

PE1 6. An isolated point charged point particle produces an electric field with magnitude E at a point 2 m away from the charge. A point at which the field magnitude is E/4 is: A) 0.5 m away from the charge B) 1 m away from the charge C) 2 m away form the charge D) 4 m away from the charge E) 8 m away from the charge

D) 4 m away from the charge

PE2 1. The magnitude of the flux of the electric field (24i−30j+16k) N/C through a 2.0 m^2 portion of the yz plane is (in units of Nm^2/C): A) 32 B) 34 C) 42 D) 48 E) 60

D) 48

PE2 11. The capacitance of a parallel-plate capacitor can be increased by: A) increasing the charge B) decreasing the charge C) increasing the plate separation D) decreasing the plate separation E) increasing the voltage

D) Decreasing the plate separation

PE3 14. Two long, insulated wires carry currents as shown in figure 3.3. Which of the following statements describes the net force and net torque on the vertical wire (with current i2)? (Hint: What is the direction of the magnetic field due to i1 above and below it?) A) The net force is zero; the net torque is clockwise B) The net force is to the left; the net torque is zero C) The net force is zero; the net torque is counterclockwise D) The net force is zero; the net torque is clockwise E) Net force and net torque are both zero.

D) The net force is zero; the net torque is clockwise

Two positive charges are equal. Which has more electric potential energy?(25.6) A. They have the same potential energy. B. Both have zero potential energy. C. Charge B. D. Charge A.

D. Charge A.

If the bar magnet is flipped over and the south pole is brought near the hanging ball, the ball will be(29.1) A. Repelled by the magnet. B. Attracted to the magnet. C. Unaffected by the magnet. D. I'm not sure.

D. I'm not sure.

Which spherical Gaussian surface has the larger electric flux?(24.4) A. Surface A. B. Not enough information to tell. C. They have the same flux. D. Surface B.

D. Surface B.

In an RC circuit, what quantity is represented by the symbol τ?(28.4) A. Period B. Torque C. Terminal voltage D. Time constant E. Coefficient of thermal expansion

D. Time constant

What are the units of potential difference?(25.3) A. Amperes B. Potentiometers C. Farads D. Volts E. Henrys

D. Volts

The magnetic field of a straight, current-carrying wire is(29.4) A. parallel to the wire. B. inside the wire. C. perpendicular to the wire. D. around the wire. E. zero.

D. around the wire.

Gauss's law applies to(24.5) A. lines. B. flat surfaces. C. spheres only. D. closed surfaces.

D. closed surfaces.

PE1 14. An electric field is set up between two parallel plates, each of area 2.0 m2, by putting 1.0 μCof charge on one plate and −1.0 μC of charge on the other. The plates are separated by 4.0 mm with their centers opposite each other, and the charges are distributed uniformly over the surface of the plates. What is the magnitude of the electric field between the plates at a distance of 1.0 mm from the positive plate, but not near the edges of the plates? A) 4.2 x 10^4 N/C B) 1.4 x 10^4 N/C C) 3.1 x 10^4 N/C D) 0.00 N/C E) 5.6 x 10^4 N/C

E) 5.6 x 10^4 N/C

PE2 4. 9 C of charge is placed on a spherical conducting shell. A particle with a charge of −3 C is placed at the center of the cavity. The net charge on the outer surface of the shell is: A)-6 C B) -3 C C) Zero D) 3 C E) 6 C

E) 6 C

PE3 12. In Ampere's law, the symbol ds is A) an infinitesimal piece of the wire that carries current i B) in the direction of B C) perpendicular to B D) a vector whose magnitude is the length of the wire that carries current i E) none of the above

E) None of the above

PE2 2. Consider Gauss's law: which of the following is true? A) if Qenc =0 then E=0 everywhere on the gaussian surface. B) E must be the electric field due to the enclosed charge. C) If a charge is placed outside the surface, then it cannot affect E at any point on the surface D) E is parallel to dA everywhere on the surface E) None of the others

E) None of the others

PE1 4. A certain physics textbook shows a region of space in which two electric field lines cross each other. We conclude that: A) at least two point charges are present B) an electrical conductor is present C) an insulator is present D) the field points in two directions at the same place E) the author made a mistake

E) The author made a mistake

PE3 10. In figure 3.2, the current element ids, point P, and the three vectors (1, 2, 3) are all in the plane of the page. The direction of dB at the point P due to this current element is: A) in the direction marked 1. B) in the direction marked 2. C) in the direction marked 3. D) out of the page E) into the page

E) into the page

PE1 8. Two particles, with charges of q1 and q2, are placed a distance r apart. The electric field is zero at a point P between the particles on the line segment connecting them. We conclude that: A) P must be midway between the particles B) q1 and q2 must have the same magnitude and sign. C) q1 and q2 must have equal magnitude and opposite signs D) q1 and q2 must have opposite signs and may have different magnitudes E) q1 and q2 must have the same sign but may have different magnitudes

E) q1 and q2 must have the same sign but may have different magnitudes

PE2 3. A charge is located at the center of a spherical volume, and the flux of the electric field through the surface of the sphere is Φ. If the radius of the sphere is tripled, what would be the new flux? A) 3Φ B) Φ/3 C) 9Φ D) Φ/9 E) Φ

E) Φ

Every minute, 120 C of charge flow through this cross section of the wire. The wire's current is(27.3) A. 60 A. B. Some other value. C. 120 A. D. 240 A. E. 2 A.

E. 2 A.

A rod attracts a positively charged hanging ball. The rod is(22.3) A. Negative. B. Positive. C. Neutral. D. Either positive or neutral. E. Either negative or neutral.

E. Either negative or neutral.

An induced current flows clockwise as the metal bar is pushed to the right. The magnetic field points(30.1) A. To the right. B. Down. C. Up. D. Out of the screen. E. Into the screen.

E. Into the screen.

A proton is released from rest at the dot. Afterward, the proton(25.1) A. Moves downward with a steady speed. B. Remains at the dot. C. Moves upward with steady speed. D. Moves upward with an increasing speed. E. Moves downward with an increasing speed.

E. Moves downward with an increasing speed.

The direction of the magnetic force on the proton is(29.7) A. Into the screen. B. The magnetic force is zero. C. To the left. D. To the right. E. Out of the screen.

E. Out of the screen.

Which of these charge distributions did not have its electric field calculated in Chapter 23?(23.1) A. a line of charge B. a parallel-plate capacitor C. A ring of charge D. A plane of charge E. They were all calculated

E. They were all calculated

The equivalent resistance for a group of parallel resistors is(28.3) E. less than any resistor in the group A. equal to the smallest resistance in the group. B. equal to the average resistance of the group. C. equal to the largest resistance in the group. D. larger than any resistor in the group.

E. less than any resistor in the group

Two protons, A and B, are next to an infinite plane of positive charge. Proton B is twice as far from the plane as proton A. Which proton has the larger acceleration? Neglect interactions between the protons.(23.4) A. Proton A B. Proton B C. both have the same acceleration

both have the same acceleration