Download (A) It is concentrated at the center of the sphere.

March 2013
AP MC Practice Problems pt2 – Electricity and Magnetism
1.
A solid conducting sphere is given a positive charge Q. How is the charge Q distributed in or on the sphere?
(A) It is concentrated at the center of the sphere.
(B) It is uniformly distributed throughout the sphere.
(C) Its density decreases radially outward from the center.
(D) Its density increases radially outward from the center.
(E) It is uniformly distributed on the surface of the sphere only.
2. One joule of work is needed to move one coulomb of charge from one point to another with no change in
velocity. Which of the following is true between the two points?
(A) The resistance is one ohm.
(B) The current is one ampere.
(C) The potential difference is one volt. (D) The electric field strength is one newton per coulomb.
(E) The electric field strength is one joule per electron.
3. A parallel–plate capacitor has a capacitance Co. A second parallel–plate capacitor has plates with twice the
area and twice the separation. The capacitance of the second capacitor is most nearly
(A) ¼Co (B) ½Co
(C) Co
(D) 2Co
(E) 4Co
4. An electron volt is a measure of
(A) energy
(B) electric field
(D) force per unit electron charge
(C) electric potential due to one electron
(E) electric charge
5. A hollow metal sphere of radius R is positively charged. Of the following distances from the center of the
sphere, which location will have the greatest electric field strength?
(A) 0 (center of the sphere) (B) 3R/2
(C) 5R/4
(D) 2R
(E) None of the above because the field is of constant strength
Questions 6-7
Charges –Q and +Q are located on the x– and y–axes, respectively, each at a distance d from the origin O, as
shown above.
6. What is the direction of the electric field at the origin O ?
c.
b.
a.
d.
e.
7. What is the magnitude of the electric field at the origin O?
(A)
kQ
2d
2
(B)
kQ
2d
2
(C)
kQ
d
2
(D)
2 kQ
d
2
(E)
2kQ
d2
8. Two charged particles, each with a charge of +q, are located along the x–axis at x = 2 and x = 4, as shown above.
Which of the following shows the graph of the magnitude of the electric field along the x–axis from the origin
to x = 6?
9. A lamp, a voltmeter V, an ammeter A, and a battery with zero internal resistance are connected as shown
above. Connecting another lamp in parallel with the first lamp as shown by the dashed lines would
(A) increase the ammeter reading
(B) decrease the ammeter reading
(C) increase the voltmeter reading
(D) decrease the voltmeter reading
(E) produce no change in either meter reading
10. Two capacitors are connected in parallel as shown above. A voltage V is applied to the pair. What is the ratio of
charge stored on C1 to the charge stored on C2, when C1 = 1.5C2 ?
(A) 4/9
(B) 2/3
(C) 1
(D) 3/2
(E) 9/4
Questions 11 – 12
The five incomplete circuits below are composed of resistors R, all of equal resistance, and capacitors C, all of
equal capacitance. A battery that can be used to complete any of the circuits is available.
11. Into which circuit should the battery be connected to obtain the greatest steady power dissipation?
(A) A (B) B (C) C (D) D (E) E
12. Which circuit will retain stored energy if the battery is connected to it and then disconnected?
(A) A (B) B (C) C (D) D (E) E
13. Kirchhoff’s loop rule for circuit analysis is an expression of which of the following?
(A) Conservation of charge (B) Conservation of energy (C) Ampere's law
(D) Faraday's law (E) Ohm's law
14. Two concentric circular loops of radii b and 2b, made of the same type of wire, lie in the plane of the page, as
shown above. The total resistance of the wire loop of radius b is R. What is the resistance of the wire loop of
radius 2b?
(A) R/4
(B) R/2
(C) R
(D) 2R
(E) 4R
Questions 15 – 16
15. What is the current I1?
(A) 0.8 mA
(B) 1.0 mA
(C) 2.0 mA
(D) 3.0 mA
16. How do the currents I1, I2, and 13 compare?
(A) I1 > I2 > I3
(B) I1 > I3 > I2
(C) I2 > I1 > I3
(E) 6.0 mA
(D) I3 > I1 > I2
(E) I3 > I2 > I1
17. If conventional electric current flows from left to right in a wire as shown, what is the direction of the magnetic
field at point P?
A) towards the top of the paper
B) towards the bottom of the paper
C) into the paper
D) out of the paper
E) to the right
18. A positive electric charge of negligible weight is released from rest between the poles of a horseshoe magnet as
shown. What would be the direction of the acceleration of the charge caused by the magnetic field?
A) towards the north pole
D) downwards
B) towards the south pole
E) none of the above
C) upwards
19. A metal spring has its ends attached so that it forms a circle. It is placed in a uniform magnetic field, as shown.
Which of the following will not cause a current to be induced in the spring?
(A) Changing the magnitude of the magnetic field
(B) Increasing the diameter of the circle by stretching the spring
(C) Rotating the spring about a diameter
(D) Moving the spring parallel to the
magnetic field
(E) Moving the spring in and out of the
magnetic field
20. A square loop of wire 0.3 meter on a side carries a current of 2
amperes and is located in a uniform 0.05-tesla magnetic field. The
left side of the loop is aligned along and attached to a fixed axis.
When the plane of the loop is parallel to the magnetic field in the
position shown, what is the magnitude of the torque exerted on
the loop about the axis?
A) 0.00225 Nm
B) 0.0090 Nm
C) 0.278 Nm
D) 1.11 Nm
E) 111 Nm
21. A strong bar magnet is held very close to the opening of a
solenoid as shown in the diagram. As the magnet is moved away
from the solenoid at constant speed, what is the direction of
conventional current through the resistor shown and what is the
direction of the force on the magnet because of the induced
current?
A)
B)
C)
D)
E)
Current through
resistor
From A to B
From B to A
From A to B
From B to A
No current
Force on Magnet
To the left
To the left
To the right
To the right
To the righ