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 87. The exam period was 75 minutes; the mean score was 47.3 the median was 46. Click here to see the formula sheet that came with the exam.

Some helpful information: • A physics 102 light bulb acts just like a resistor: its resistance is constant, independent of the current flowing through the light bulb. The bulb's brightness increases with increasing current. • 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 charge Q_{1} = +2 μC is fixed at (0,+3); a second charge Q_{2} = -2 μC is fixed at (0,-3). There are initially no charges at points P (+3,0), A (+3,2), and B (5,0), which are labeled for the sake of reference.

Points B and P lie along the same equipotential curve.

(T) True (F) False

(a) A particle put at point B must be a positive charge: Q_{B} > 0. (b) A particle put at point B must be a negative charge: Q_{B} < 0. (c) A particle put at point B must be uncharged: Q_{B} = 0.

(a) 6 × 10^{-6} N (b) 9 × 10^{-6} N (c) 1.5 × 10^{-5} N

A third charge will be brought onto the x-axis from infinity. To which of the following points on the x-axis could we bring that charge without doing any net work?

(a) x = 4 m (b) x = 2 m (c) x = 1 m (d) x = -4 m (e) Need to know the value of the charge being brought from infinity.

(a) The potential inside that cylinder must be zero. (b) The electric field inside that cylinder must be zero. (c) Both (a) and (b) are true.

(a) 0.27 (b) 0.43 (c) 0.68

Find the rate at which the battery delivers energy to this circuit.

(a) 2.33 W (b) 4.66 W (c) 5.63 W (d) 15.9 W (e) 18.0 W

(a) 0.27 A (b) 0.41 A (c) 0.65 A (d) 0.68 A (e) 0.79 A

(a) The current through the 20 Ω resistor would decrease. (b) The current through the 20 Ω resistor would not change. (c) The current through the 20 Ω resistor would increase.

In this circuit, the resistors are R_{1} = 14 Ω, R_{2} = 25 Ω, R_{3} = 8 Ω, R_{4} = 30 Ω, and R_{5} = 20 Ω. What is the resistance between points A and B?

(a) 4.3 Ω (b) 9.8 Ω (c) 10.9 Ω (d) 19.5 Ω (e) 24.2 Ω

(a) 0.0009 W (b) 0.0016 W (c) 0.02 W

Four capacitors are connected, as shown, to an unspecified battery.

What is the total capacitance of the four capacitors, connected as shown?

(a) 5.4 μF (b) 12 μF (c) 27 μF (d) 33 μF (e) 71 μF

(a) 240 μC (b) 360 μC (c) 720 μC

The 1.5 μF capacitor in this circuit is initially uncharged. The resistances are as shown in the diagram, but the battery voltage is unknown. The switch is then set to position A. After a very long time, the voltage across the capacitor is 18 volts.

What is the battery voltage?

(a) 18 V (b) 24 V (c) 27 V

(a) 15 mA (b) 30 mA (c) 45 mA

(a) 2.4 mW (b) 4.8 mW (c) 9.6 mW (d) 270 mW (e) 540 mW

(a) More is converted to heat if the switch is set to B. (b) More is converted to heat if the switch is set to C. (c) The same amount of energy is converted to heat in each case.

Two capacitors are connected to a battery, as shown. Assume initially that C_{1} = 6 μF, C_{2} = 18 μF, and V_{b} = 12 volts. There will be some resulting voltage across the second (C_{2} = 18 μF) capacitor. Now fill the region between the plates of that second capacitor with a dielectric of constant 1.67.

What happens to the voltage across that second capacitor as a result of inserting the dielectric? Compare that voltage after inserting the dielectric with the voltage before.

(a) It decreases by two volts. (b) It decreases by one volt. (c) It does not change. (d) It increases by one volt. (e) It increases by two volts.

(a) making the plate separation 5/3 of its original value (b) making the plate separation 3/5 of its original value

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

(a) I_{1} + I_{2} = I_{3} (b) I_{1} + I_{2} + I_{3} = 0 (c) Neither the equation in (a) nor the equation in (b) is correct.

(a) V_{4} - I_{3}R_{5} = 0 (b) V_{4} + I_{3}R_{5} = 0 (c) Neither the equation in (a) nor the equation in (b) is correct.

(a) V_{1} - I_{1}R_{1} + I_{1}R_{2} - V_{2} = 0 (b) V_{1} - I_{1}R_{1} - I_{1}R_{2} - V_{2} = 0 (c) V_{1} - I_{1}R_{1} + I_{2}R_{2} - V_{2} = 0