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 126. The exam period was 90 minutes; the mean score was 69.0; the median was 66. Click here to see the formula sheet that came with the exam.

What is the magnitude of the electric field at point P [with coordinate (0, 2)] due to charges q_{1} and q_{2}?

(a) 1798 N/C (b) 1608 N/C (c) 899 N/C (d) 804 N/C (e) 0 N/C

Three charges are fixed at (-4,0), (+4,0), and (0,-1) as shown in the figure: q_{1} = +2 μC, q_{2} = -2 μC, and q_{3} = +0.5 μC.

What is the direction of the electric field at point P due to all three charges?

(a) pointing up (b) pointing to the upper left (c) pointing to the upper right

(a) 11038 J/C (b) 8041 J/C (c) 4495 J/C (d) 2997 J/C (e) 1498 J/C

(a) 1.026 × 10^{-3} N (b) 1.058 × 10^{-3} N (c) 2.052 × 10^{-3} N (d) 2.116 × 10^{-3} N (e) 2.554 × 10^{-3} N

(a) 2.31 × 10^{-3} J (b) 4.49 × 10^{-3} J (c) 6.67 × 10^{-3} J (d) 8.99 × 10^{-3} J (e) 0 J

A hollow conducting cylinder is held fixed between two large parallel conducting planes that are also fixed in position. The left plane contains positive charge while the right plane contains an equal amount of negative charge. The total charge on the conducting cylinder is zero. Note that only one of the diagrams A, B, C, and D is correct.

Which figure shows the correct pattern for field lines?

(a) A (b) B (c) C (d) D (e) B and D

(a) The charge distribution is uniformly zero everywhere on the cylinder. (b) There is a net negative charge on the left half of the cylinder and a net positive charge on the right half of the cylinder. (c) There is a net positive charge on the left half of the cylinder and a net negative charge on the right half of the cylinder.

(a) to the left (b) to the right (c) The charge will not move.

(a) to the left (b) to the right (c) The sphere will not move.

The battery supplies 15 W of power to the circuit. What is the value of R ?

(a) R = 10 Ω (b) R = 15 Ω (c) R = 30 Ω (d) R = 45 Ω (e) R = 60 Ω

(a) double. (b) remain the same. (c) halve.

A doped semiconductor has a resistivity of ρ =10^{-3} Ωm. If a 1 micrometer thick slab of this material is to be cut into a resistor equaling 100 Ω, what dimensions should be chosen? (Note: the length-to-width-to-thickness ratio of the slab shown in the figure is not necessarily similar to the correct answer.)

(a) w = 10 μm and L = 1 μm (b) w = 1 μm and L = 1 μm (c) w = 1 μm and L = 100 μm (d) w = 0.1 μm and L = 100 μm (e) w = 100 μm and L = 1 μm

(a) 5 Ω (b) 10 Ω (c) 20 Ω (d) 40 Ω (e) 80 Ω

Five capacitors are hooked across a 10 V battery as shown. What is the potential difference, V_{A}-V_{B}?

(a) 0.91 V (b) 1.00 V (c) 1.11 V (d) 5.00 V (e) 6.00 V

(a) 10.0 μJ (b) 25.0 μJ (c) 33.3 μJ (d) 50.0 μJ (e) 250 μJ

An isolated parallel plate capacitor contains charge ±10 μC on its plates, corresponding to a potential difference of 10 V. The initial separation between the plates is d. Later, the distance between the plates is increased by a factor of two while the charge on each plate remains unchanged.

What is the voltage between the two plates after the separation becomes 2d ?

(a) 2.5 V (b) 5 V (c) 10 V (d) 20 V (e) 40 V

(a) greater than in the charged capacitor with plate separation d. (b) the same as in the charged capacitor with plate separation d. (c) less than in the charged capacitor with plate separation d.

The potential difference between the plates of the left capacitor is 10 V. Which one of these statements is true?

(a) The energy stored by the capacitor on the right is half that stored by the capacitor on the left. (b) The energy stored by the capacitor on the right is the same as that stored by the capacitor on the left. (c) The energy stored by the capacitor on the right is twice that stored by the capacitor on the left.

(a) U_{1} = U_{2} and Q_{1} = Q_{2} (b) U_{1} = 2U_{2} and 2Q_{1} = Q_{2} (c) 2U_{1} = U_{2} and 2Q_{1} = Q_{2} (d) U_{1} = 2U_{2} and Q_{1} = 2Q_{2} (e) 2U_{1} = U_{2} and Q_{1} = 2Q_{2}

(a) decreases since the current from the battery splits between the resistor and the bulb. (b) remains the same since the battery maintains a constant voltage across the bulb. (c) increases since the battery drives more power into the circuit after the switch closes.

(a) decreases since the current passes in parallel through both the resistor and the bulb. (b) remains the same since the battery maintains a constant voltage across the bulb. (c) increases since the battery drives more power into the circuit after the switch closes.

(a) decreases noticeably since no current flows from the battery through the bulb. (b) is almost unchanged since voltage across the bulb is now provided by the capacitor. (c) increases noticeably since the capacitor is now free to discharge through the bulb.

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

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

(a) 7.38 V (b) 14.22 V (c) 17.78 V (d) 21.33 V (e) 24.62 V

Referring to the circuit above, which one of the following equations is correct?

(a) V_{battery 1} - V_{battery 2} = I_{3}R_{3} (b) I_{1}R_{1} + I_{2}R_{2} + I_{3}R_{3} = I_{1}V_{battery 1} + I_{2}V_{battery 2} (c) I_{1} + I_{2} = I_{3}

In the circuit shown at right, the switch is initially open. At time t = 0 the switch is closed. Which of the above graphs best represents the voltage at point A as a function of time?

(a) (b) (c)

Two similar circuits are shown in the above figure. Note that the battery voltages and capacitances in the two circuits are different. For times t < 0, switch s_{1} is closed and switch s_{2} is open in both circuits. At t = 0, s_{1} is opened and s_{2} is closed in both circuits. The time for which the voltages at the points labeled A in the circuits will be the same is

(a) t = 0 (b) t = 6.93 × 10^{-3} seconds (c) t = 13.86 × 10^{-3} seconds (d) t = 15.00 × 10^{-3} seconds (e) The voltages are never the same for finite values of t.