This exam consists of 21 questions; 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 105. When the exam was given, the mean was 75.0; the median was 75. Click here to see the formula sheet that came with the exam.

(a) both neutral (b) both positive (c) both negative (d) L negative and M positive (e) L positive and M negative

(a) left (b) right (c) up (d) down (e) the force is zero

(a) N C^{2} (b) C/N (c) N (d) N/C (e) N/m^{2}

Four charges are fixed at the corners of a square of sides 4 m as shown.

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

(a) - 46.63 N-m/C (b) - 19.1 N-m/C (c) 0 N-m/C (d) + 19.1 N-m/C (e) + 46.3 N-m/C

(a) 7.0 N/C (b) 13.5 N/C (c) 18.7 N/C (d) 27.5 N/C (e) 42.0 N/C

(a) along the vertical (b) along the horizontal (c) along the diagonal

(a) 0.42 × 10^{-8} N (b) 0.59 × 10^{-8} N (c) 1.19 × 10^{-8} N (d) 1.93 × 10^{-8} N (e) 2.45 × 10^{-8} N

(a) by arbitrary convention. (b) because the proton charge is positive. (c) because like charges repel. (d) because glass is an insulator. (e) because silk is conducting.

A small particle with charge +15e (e = 1.6x10^{-19} C) is located at the origin, a distance of 5 nm from a second particle of charge –30e.

What is the potential energy of the two-charge system?

(a) -6.90 × 10^{-9} J (b) -8.98 × 10^{-12} J (c) -3.33 × 10^{-15} J (d) -2.07 × 10^{-17} J (e) -4.15 × 10^{-19} J

(a) - 2.50 nm (b) 2.89 nm (c) 3.71 nm (d) 7.35 nm (e) - 5.00 nm

(a) 0 J (b) 6.65 × 10^{-19} J (c) 9.56 × 10^{-19} J (d) 1.24 × 10^{-18} J (e) 5.18 × 10^{-18} J

Four capacitors are connected as shown below. A 15 V battery is centered in the circuit. Assume that all of the capacitors are fully charged and that no current is flowing.

What is the charge on one of the plates of the 4 mF capacitor?

(a) Q_{4} = 15 mC (b) Q_{4} = 30 mC (c) Q_{4} = 60 mC

(a) U_{tot} = 0.054 × 10^{-3} J (b) U_{tot} = 0.420 × 10^{-3} J (c) U_{tot} = 0.875 × 10^{-3} J (d) U_{tot} = 1.125 × 10^{-3} J (e) U_{tot} = 2.660 × 10^{-3} J

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

(a) C_{eq} = C_{0} / 4 (b) C_{eq} = C_{0} / 2 (c) C_{eq} = C_{0} (d) C_{eq} = 2C_{0} (e) C_{eq} = 5C_{0}

An isolated parallel-plate capacitor has area A = 3.0 × 10^{-4} m^{2} and plate separation d = 2 × 10^{-5} m. The charge on each plate has magnitude Q = 11 nC. The capacitor is initially filled with air (k = 1).

Compute the capacitence of the capacitor.

(a) C = 2.31 × 10^{-9 }F (b) C = 4.32 × 10^{-8 }F (c) C = 9.06 × 10^{-6 }F (d) C = 0.4 × 10^{-9 }F (e) C = 0.133 × 10^{-9 }F

(a) U = 2.31 × 10^{-8 }J (b) U = 4.32 × 10^{-8 }J (c) U = 9.06 × 10^{-8 }J (d) U = 1.51 × 10^{-7 }J (e) U = 4.56 × 10^{-7 }J

(a) increases by a factor of 2. (b) decreases by a factor of 2. (c) remains the same.

(a) Q_{2} > Q_{1} (b) Q_{2} = Q_{1} (c) Q_{2} < Q_{1}

An electronic circuit is constructed as shown in the figure. The switch S is open.

The effective resistance of the circuit is

(a) 95 W (b) 80 W (c) 35 W