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A grounded spherical conductor is on an insulating stand. A positively charged rod is brought close to the sphere but does not touch the sphere, as shown. The rod is moved far away and then the grounding wire is removed.
1. Which of the following describes the resulting charge on the sphere? (A) Positive (B) Negative (C) No net charge and no charge polarization (D) No net charge, but it is polarized with more negative charges on the left side of the sphere
Ammeters and are placed in a circuit that consists of a battery and different resistors , , and , as shown. Ammeter measures a current of and Ammeter measures a current of.
2. What is the current in Resistor?
(A) (B) (C) (D)
AP PHYSICS C: ELECTRICITY AND MAGNETISM Test Booklet
Practice Exam 2 MCQ
AP Physics C: Electricity and Magnetism Page 1 of 21
The figure shows equipotential lines in a region containing three charged objects.
3. Which of the following correctly indicates the direction of the electric field at Point^ and provides a valid justification?
Direction Justification
A
The electric field is directed perpendicular to the equipotential lines and toward decreasing electric potential.
B
The electric field is in the same direction as the electric force exerted on a negatively charged object.
C
The electric field is directed perpendicular to the equipotential lines and toward increasing electric potential.
D
The electric field is in the same direction as the electric force exerted on a positively charged object.
Practice Exam 2 MCQ
Page 2 of 21 AP Physics C: Electricity and Magnetism
Two uniformly charged nonconducting spheres, each with diameter , are placed such that their surfaces are separated by a distance , as shown. The magnitudes of the charges of the spheres are and , as indicated in the figure.
6. What is the magnitude of the electric force exerted by one sphere on the other?
(A)
(B)
(C)
(D)
Two spheres each with charge are held fixed on the -axis at positions and , as shown. A positively charged particle with charge is placed on the -axis and released from rest at a position slightly above the origin.
7. Which graph best represents the particle’s speed as a function of time as the particle moves along the -axis?
Practice Exam 2 MCQ
Page 4 of 21 AP Physics C: Electricity and Magnetism
(A)
(B)
(C)
(D)
Sphere of radius has a spherically symmetric charge density that is described by , where is a constant and is the radial distance from the center of the sphere. The total charge of Sphere is. Sphere has radius and also has the same spherically symmetric charge density described by.
8. What is the total charge of Sphere?
(A) (B) (C) (D)
9. The plates of an isolated, charged parallel-plate capacitor are moved apart. Which of the following correctly indicates how the capacitance of the capacitor changes and provides a valid justification? (A) Decreases, because the amount of charge on the plates of the capacitor decreases. (B) Decreases, because the potential difference across the capacitor plates increases. (C) Does not change, because the area of the capacitor plates does not change.
(D) Does not change, because the potential difference increases by the same factor as the distance between the plates increases.
Practice Exam 2 MCQ
AP Physics C: Electricity and Magnetism Page 5 of 21
12. Which of the following provides a correct description of the types of materials in these nails and provides valid reasoning?
Nail Nail Reason
A Ferromagnetic Ferromagnetic
Both materials become magnetized in the presence of a magnet.
B Ferromagnetic Paramagnetic
A ferromagnetic material retains some of the strength of the magnetic field after the magnet is removed. A paramagnetic material loses all its magnetic field strength when the magnet is removed.
C Paramagnetic Ferromagnetic
A paramagnetic material retains some of the strength of the magnetic field after the magnet is removed. A ferromagnetic material loses all its magnetic field strength when the magnet is removed.
D Paramagnetic Paramagnetic
Both materials become magnetized and drop some of the iron filings when the magnet is removed.
(A) A
(B) B
(C) C
(D) D
Two conducting spheres, and , are attached to nonconducting stands. Sphere has a radius of and Sphere has a radius of. Both spheres initially have net charges of. The spheres are brought into contact with one another, and then separated and moved far away from each other.
Practice Exam 2 MCQ
AP Physics C: Electricity and Magnetism Page 7 of 21
13. Which of the following correctly indicates the final charges on the spheres after they are separated and moved far away from each other?
Sphere Sphere
A
B
C
D
(A) A
(B) B
(C) C
(D) D
Two wires perpendicular to the -axis carry identical currents out of the page, as shown. Each wire is a perpendicular distance from the -axis. Point is on the -axis at the coordinate and Point is on the x-axis at the coordinate
.
14. Which of the following best represents the direction, if any, of the net magnetic field at Point?
(A)
(B)
(C)
(D) No direction, because the magnetic field at Point is zero
Practice Exam 2 MCQ
Page 8 of 21 AP Physics C: Electricity and Magnetism
17. What is the magnitude of the potential difference across the inductor at time? (A) (B) (C) (D)
Two resistors of resistance are connected in series to a battery with Ɛ and internal resistance. The battery has a
terminal voltage of.
18. Which expression is equal to the current in the battery?
(A)
(B)
(C)
Ɛ
(D)
Ɛ
The figure shows the electric potential as a function of position along the -axis. Points , , , and are indicated.
19. Which of the following correctly compares the magnitudes of the^ -components of the electric fields^ ,^ ,^ , and , at points , , , and , respectively?
Practice Exam 2 MCQ
Page 10 of 21 AP Physics C: Electricity and Magnetism
(A)
(B)
(C)
(D)
The diagram shows six identical resistors of resistance connected to a battery with Ɛ.
20. What is the equivalent resistance of the circuit shown? (A)
(B)
(C)
(D)
A rectangular conducting loop is located above a long, straight wire carrying a current to the right, as shown. The wire and loop are both in the plane of the page.
21. Which of the following actions would cause a clockwise current to be induced in the loop?
(A) Moving the loop to the right (B) Moving the loop out of the page while keeping the same orientation (C) Moving the loop away from the wire (D) Moving the loop toward the wire
Practice Exam 2 MCQ
AP Physics C: Electricity and Magnetism Page 11 of 21
(A)
(B)
(C)
(D)
A square loop of area is in the -plane, as shown, and the area vector of the loop is directed in the -direction. The loop is in a region of a uniform, time-varying magnetic field. The -component of the magnetic field varies as a function of time as described by.
24. Which graph correctly represents the magnetic flux through the loop as a function of time?
Practice Exam 2 MCQ
AP Physics C: Electricity and Magnetism Page 13 of 21
(A)
(B)
(C)
(D)
A proton is held in place at the origin. Points and are located on the -axis at locations and , where .
25. Which integral could be used to determine the electric potential difference from Point to Point?
Practice Exam 2 MCQ
Page 14 of 21 AP Physics C: Electricity and Magnetism
27. Which of the following correctly describes the acceleration of the bar and provides a valid justification? (A) The acceleration is zero because the resistor is not in the magnetic field.
(B) The acceleration is zero because the magnetic force creates a charge separation across the ends of the bar but does not oppose the motion of the bar.
(C) The acceleration is nonzero because there will be a current in the bar due to the induced and the magnetic field will exert a force on the current-carrying bar.
(D) The acceleration is nonzero because the electric field created by the charge separation in the bar will exert a force on the bar.
Conducting spheres , , and are initially very far apart. Spheres and each have radius and no net charge and Sphere has radius and charge , as shown. The three spheres are then connected to each other by ideal wires (not shown) until the spheres reach electrostatic equilibrium and the wires are removed.
28. What is the final net charge on Sphere?
(A) (B)
(C) (D)
An external force exerted on a small sphere with net charge results in the sphere moving to the right with constant speed parallel to a wire carrying current , as shown. The sphere is a distance from the wire.
Practice Exam 2 MCQ
Page 16 of 21 AP Physics C: Electricity and Magnetism
29. Which expression is equal to the magnitude of the magnetic force exerted on the sphere?
(A)
(B)
(C)
(D)
A circuit consists of two resistors of resistances and , a capacitor of capacitance μ , and a battery with potential difference , as shown. The circuit has been connected for a long time.
30. What is the charge on the positive plate of the capacitor?
(A) Zero (B) μ (C) μ (D) μ
A charged particle is released from rest in an electric field. After the particle has moved through a potential difference of , the particle has speed.
31. If the particle then moves through an^ additional potential difference of^ , what would be the final speed of the particle?
(A)
(B)
(C)
(D)
Practice Exam 2 MCQ
AP Physics C: Electricity and Magnetism Page 17 of 21
In Scenario , a charged capacitor of capacitance is connected to two resistors with resistance and two switches, and , as shown. Switch is closed and the potential difference across the capacitor decreases to of its initial value in time. Scenario is identical to Scenario except both switches are closed at the same time. The potential difference across the capacitor decreases to of its initial value in time.
35. What is the ratio?
(A)
(B)
(C) (D)
36. The current density in a cylindrical conductor of radius^ varies with radial position^ according to . Which expression is equal to the current in the conductor?
(A)
(B)
(C)
(D)
Two parallel plate capacitors are connected in series, as shown. Both capacitors have plates of area and plate separation
. One of the capacitors is completely filled with a material of dielectric constant. 37. Which expression is equal to the equivalent capacitance of the two capacitors?
Practice Exam 2 MCQ
AP Physics C: Electricity and Magnetism Page 19 of 21
(A)
(B)
(C)
(D)
Two small spheres are arranged along a line and have net charges of and , as shown. The vertical tick marks are all equally spaced.
38. At which of the labeled locations in the figure is the electric potential the greatest?
(A) (B) (C) (D)
A square loop is in a uniform magnetic field directed out of the page, as shown. The loop spins about the dashed axis that passes through the center of the loop. The magnetic flux through the loop as a function of time is described by
, where and.
39. What is the absolute value of the induced in the loop at?
Practice Exam 2 MCQ
Page 20 of 21 AP Physics C: Electricity and Magnetism
