True-false questions are worth 2 points each, three-choice multiple choice questions are worth 3 points each, five-choice multiple choice questions are worth 6 points each. The maximum possible score is 114. The exam period was 90 minutes; the mean score was 71.7 the median was 77. Click here to see page1 page2 page3 of the formula sheet that came with the exam.

Some helpful information: • A reminder about prefixes: p (pico) = 10^{-12}; n (nano) = 10^{-9}; μ (micro) = 10^{-6}; m (milli) = 10^{-3}; k (kilo) = 10^{+3}; M or Meg (mega) = 10^{+6}; G or Gig (giga) = 10^{+9}.

(a) The conductor moves away from point A. (b) The conductor does not move. (c) The conductor moves toward point A.

(a) 300 N/C (b) 2940 N/C (c) 5600 N/C

The dipoles are arranged so that the four point charges which compose the dipoles alternate to form a square of side length d = 1.25 cm, as in the figure.

What is the magnitude and direction of the electrostatic force on the bottom dipole (i.e., the sum of the forces felt by each charge which the dipole comprises?)

(a) 12.2 N, towards the other dipole (b) 7.87 N, towards the other dipole (c) 0 N (d) 7.87 N, away from the other dipole (e) 12.2 N, away from the other dipole

(a) 0 N/C (b) 1.3 × 10^{4} N/C (c) 1.8 × 10^{4} N/C (d) 2.5 × 10^{4} N/C (e) 3.6 × 10^{4} N/C

(a) The electron is stationary. (b) 1.9 × 10^{5} m/s (c) 2.2 × 10^{6} m/s (d) 3.4 × 10^{6} m/s (e) 3 × 10^{8} m/s

(a) 0.33 m/s (b) 0.66 m/s (c) 0.99 m/s

(a) 1.67 pF (b) 5 pF (c) 15 pF (d) 45 pF (e) 90 pF

Two parallel plates separated by a small distance d are given a charge Q to form a capacitor. The capacitor is not connected to a battery. The distance between the two plates is then doubled. Which one of the following is correct?

(a) The electric field doubles, but not the voltage across the plates nor the charge on the plates. (b) The electric field and the voltage double, but not the charge on the plates. (c) The voltage doubles, but not the electric field or the charge on the plates.

(a) The potential energy decreases. (b) The potential energy remains the same. (c) The potential energy increases.

Four positive charges, each with charge +Q, are placed at the corners of a square five centimeters on a side. The work done by you to assemble these charges is 100 J.

What must be the charge Q on each particle?

(a) 5.2 μC (b) 6.2 μC (c) 10.1 μC (d) 12.8 μC (e) 14.4 μC

(a) -100 J (b) 0 J (c) 100 J

What is the total energy stored in the capacitors in the system?

(a) 1.9 ×10^{-6} J (b) 2.6 ×10^{-6} J (c) 1.1 ×10^{-5} J

Three charges are placed on the corners of a square with sides of length 5 cm as shown.

What is the electric potential at the center of the square?

(a) -14363 V (b) -509 V (c) -255 V (d) 420 V (e) 1525 V

(a) -2 nC (b) -1 nC (c) 0 nC (d) 1 nC (e) 2 nC

With the switch S open, what is the current through resistance R_{1}.

(a) (b) (c)

(a) I_{1}(open) < I_{1}(closed) (b) I_{1}(open) = I_{1}(closed) (c) I_{1}(open) > I_{1}(closed)

(a) 4.43 A (b) 3.12 A (c) 2.61 A (d) 1.20 A (e) 0.86 A

A resistor of 5 Ω with the dimensions given above is in a circuit with a battery and light bulb.

If the power dissipated in the resistor is 5 W, what is the voltage across the resistor?

(a) 5 V (b) 6 V (c) 9 V

(a) 13 Ω (b) 10 Ω (c) 2.5 Ω

R_{1} = R_{2} = R_{3} = R_{4} = 4 Ω.

(a) 1.7 Ω (b) 1.5 Ω (c) 2.4 Ω (d) 8.0 Ω (e) 10.2 Ω

Which one of the following equations describing this circuit is incorrect?

(a) ε_{1} - I_{1}R_{1} - I_{3}R_{3} + ε_{3} - I_{1}R_{4} = 0 (b) ε_{2} - I_{2}R_{2} - I_{3}R_{3} + ε_{3} = 0 (c) I_{1} = I_{2} + I_{3}

(a) 1.06 A (b) 2.50 A (c) 3.33 A (d) 4.70 A (e) 6.23 A

(a) 15.8 mF (b) 10.2 mF (c) 3.3 mF

The circuit above contains three capacitors, a resistor, battery and switch. The circuit switch starts in position A. There is no initial charge on the capacitors.

ΔV = 12.0 V, R = 200 Ω, C_{1} = 10.0 μF, C_{2} = C_{3} = 20.0 μF.

At t = 0, the switch is flipped to position B.

What is the charge on the capacitor C_{1} at t = 0 just after the switch is closed?

(a) 0 μC (b) 80 μC (c) 120 μC

(a) 0 mA (b) 15.0 mA (c) 30.0 mA (d) 40.0 mA (e) 60.0 mA

(a) 0 μC (b) 48.0 μC (c) 72.0 μC (d) 96.0 μC (e) 144 μC