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 132. The exam period was 90 minutes; the mean score was 100.5; the median was 102. Click here to see the formula sheet that came with the exam.

Sphere A is a metal sphere of radius 7 mm with a charge of +5 μC. Sphere B is a metal sphere of radius 7 mm with a charge of -5 μC.

Sphere A and sphere B are placed 1.5 m apart. What is the approximate magnitude of the force between them?

(a) 0 N (b) 0.10 N (c) 0.27 N (d) 0.39 N (e) 0.44 N

(a) equal to the magnitude of the force in the previous question. (b) different from magnitude of the force in the previous question.

(a) v = 300 km/s (b) v = 750 km/s (c) v = 1310 km/s (d) v = 1850 km/s (e) v = 2180 km/s

Two charges, one of +12 μC, the other of +3 μC, are 3 cm apart, as shown in the figure.

Where does the total electric field due to these two charges vanish?

(a) 2 cm left of the +12 μC charge (b) 1 cm left of the +12 μC charge (c) 1 cm right of the +12 μC charge (d) 2 cm right of the +12 μC charge (e) 4 cm right of the +12 μC charge

(T) True (F) False

(a) (b) (c)

(a) greatest near the positively charged plate. (b) uniform throughout the region. (c) greatest near the negatively charged plate.

(a) (b)

Four point charges are arranged in this configuration. Each grid line is 1m.

Calculate the x-component of the electric field at (0,3) due to the four charges shown.

(a) E_{x} = 1.23 × 10^{3} N/C (b) E_{x} = 2.62 × 10^{3} N/C (c) E_{x} = 3.46 × 10^{3} N/C (d) E_{x} = 5.43 × 10^{3} N/C (e) E_{x} = 6.78 × 10^{3} N/C

(a) E_{y} = -1.60 × 10^{4} N/C (b) E_{y} = -3.94 × 10^{4} N/C (c) E_{y} = -5.12 × 10^{4} N/C (d) E_{y} = -6.89 × 10^{4} N/C (e) E_{y} = -7.14 × 10^{4} N/C

(a) 1.08 × 10^{-5} N (b) 2.27 × 10^{-5} N (c) 4.73 × 10^{-5} N (d) 9.26 × 10^{-5} N (e) 1.40 × 10^{-4} N

(a) 3.19 × 10^{3} V (b) 4.04 × 10^{3} V (c) 7.39 × 10^{3} V (d) 2.40 × 10^{4} V (e) 8.18 × 10^{4} V

(a) -1.40 × 10^{-2} J (b) -3.15 × 10^{-2} J (c) -5.43 × 10^{-2 }J (d) -8.76 × 10^{-2 }J (e) -9.80 × 10^{-2} J

(a) greater than the magnitude of the force on the -6 μC charge. (b) equal to the magnitude of the force on the -6 μC charge. (c) less than the magnitude of the force on the -6 μC charge.

(a) increase. (b) remain the same. (c) decrease.

An isolated parallel-plate capacitor has area A = 2.0 × 10^{-4} m^{2} and plate separation d = 3 × 10^{-5} m. The charge on each plate has magnitude Q = 15 μC. The capacitor is initially filled with air (κ = 1).

Compute the energy stored in the capacitor.

(a) 1.91 J (b) 3.83 J (c) 5.24 J (d) 8.39 J (e) 9.56 J

What is the resistance between point A and B when the switch is open?

(a) 10 kΩ (b) 20 kΩ (c) 30 kΩ (d) 40 kΩ (e) 50 kΩ

(a) 3.33 kΩ (b) 10.56 kΩ (c) 14.29 kΩ (d) 29.12 kΩ (e) 106.04 kΩ

Which circuit shown below is wired so that either switch can turn on the lamp, regardless of the state of the other switch? The correct answer to this question is called "three-way wiring," and is probably used in your apartment or dormitory.

The switch in each circuit has been open for a very long time.

Which one of the graphs shown below most accurately describes the behavior of the current through the resistor after the switch in any of the circuits is closed?

(a) 0.11 A (b) 0.45 A (c) 0.67 A (d) 0.99 A (e) 1.56 A

(a) 1 μC (b) 2 μC (c) 3 μC (d) 5 μC (e) 6 μC

What should be the resistance of the resistor so that the lamp works as designed?

(a) 0.12 Ω (b) 0.54 Ω (c) 2.67 Ω (d) 5.78 Ω (e) 98 Ω

(a) 0.13 mA (b) 0.87 mA (c) 0.94 mA (d) 1.24 mA (e) 5.99 mA

(a) 1.0 kΩ (b) 2.5 kΩ (c) 3.8 kΩ (d) 6.5 kΩ (e) 9.9 kΩ