This exam consists of 29 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 120. When the exam was given, the mean was 75.1; the median was 75. Click here to see the formula sheet that came with the exam.

A negatively charged rod is brought close to an isolated conducting sphere. The net charge on the sphere is zero. The net force between the rod and the sphere is

(a) zero. (b) attractive. (c) repulsive.

(a) zero (b) positive (c) negative

(T) True (F) False

(a) (b) (c)

Which one of the following describes the function of the Electromotive Force (emf)?

(a) It produces charge. (b) It pushes charge. (c) It provides a constant current.

(a) It provides a constant power. (b) It maintains a constant potential difference.

(a) ρ_{A} = ρ_{B} (b) ρ_{A} = ρ_{B} / 2 (c) ρ_{A} = ρ_{B} / 4 (d) ρ_{A} = 2 ρ_{B} (e) ρ_{A} = 4 ρ_{B}

A uniform electric field is set up between the two parallel plates of a capacitor at a potential difference of 200 V. The distance between the two plates is 0.5 cm.

What is the magnitude of the electric field between the two plates?

(a) 4 × 10^{4} N/C (b) 2 × 10^{4} N/C (c) 8 × 10^{3} N/C (d) 4 × 10^{3} N/C (e) 1.6 × 10^{3} N/C

(a) 1.6 joules (b) 0.4 joules (c) 0.25 joules (d) 0.03 joules (e) 0.01 joules

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

Eight small conducting spheres (open circles) are fixed at regular intervals on a circle with radius R = 1.2 m in the xy-plane. Each one is charged with 2 nC of positive charge.

What is the electric field strength |E| at the center of the circle?

(a) 100 N/C (b) 0 N/C (c) -100 N/C

(a) to the right, along the x axis (b) out of the paper, along the z axis (c) does not point anywhere, because the field strength is zero

(a) 120 V (b) 100 V (c) 0 V (d) -100 V (e) -144 V

(a) 65 cm/s (b) 59 m/s (c) 6.5 × 10^{2} m/s (d) 5.9 × 10^{4} m/s (e) 6.5 × 10^{6} m/s

(a) 120 μC (b) 34 × 10^{-3} C (c) 0.52 C (d) 13 C (e) 4.2 × 10^{2} C

The resistors R_{1} and R_{2} each have resistance 10 Ω. The capacitors C_{1}, C_{2} and C_{3} all have capacitance 1 μF. The battery supplies a potential difference of 10 V. A perfect ammeter (without resistance) is connected in the lower left of the circuit, as shown in the figure. The switch on the top right is initially in the open position, and the capacitors are fully charged.

What is the current I through the ammeter with the switch open?

(a) 0.0 A (b) 1.0 A

(a) 0.33 μF (b) 0.5 μF (c) 0.67 μF (d) 2 μF (e) 3 μF

(a) 1.11 μC (b) 2.22 μC (c) 3.33 μC (d) 4.44 μC (e) 6.67 μC

(a) 0.5 A (b) 1.0 A (c) 2.0 A

(a) 0 μC (b) 2.5 μC (c) 5.0 μC

The circuit below represents a circuit that contains a battery that supplies a potential difference V_{0} = 10 V, a resistor R_{1} = 100 kΩ and a capacitor C. Initially, no charge is stored on C and the switch is in the open position (as shown in the figure).

The switch is now closed. What is the current through R_{1} at the moment just after the switch connects?

(a) 0 mA (b) 1 × 10^{-4}A (c) 1 × 10^{6}A

(a) 5.32 μC (b) 63.6 μC (c) 126 μC (d) 3.24 × 10^{-4} C (e) 5.32 × 10^{-2} C

(a) V_{new} > V_{old} (b) V_{new} = V_{old} (c) V_{new} < V_{old}

What single, equivalent resistor could replace all of the resistors in the circuit?

(a) 20 ohms (b) 12 ohms (c) 6 ohms (d) 4 ohms (e) 3 ohms

(a) 0.5 A (b) 1.0 A (c) 2.0 A (d) 4.0 A (e) 6.0 A