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 95. The exam period was 75 minutes; the mean score was 66.4 the median was 66. Click here to see page1 page2 page3 of 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}.

Does the generator attract the neutral hanging sphere?

(a) Yes, the van de Graaff generator attracts the hanging metal sphere. (b) No, the van de Graaff generator does not attract the hanging metal sphere.

(a) They induce negative charge on the grounded sphere. (b) They induce positive charge on the grounded sphere. (c) They cannot induce a charge on the neighboring sphere as long as that sphere is grounded.

Positive charges, each equal to = 4 nC, are located at (x = -5 m, y = 12 m) and (x = 5 m, y = 12 m); and a negative charge q = -4 nC is located at (x = 0, y = 12 m).

At the origin, the x-component of the electric field E_{x} equals:

(a) 0.14 N/C (b) 0.086 N/C (c) 0 (d) -0.086 N/C (e) -0.14 N/C

(a) 43.2 nJ (b) 10.1 nJ (c) 0 (d) -10.1 nJ (e) -43.2 nJ

A positive charge q_{1} = 8 nC is located at the origin. A second positive charge, q_{2} = 5 nC, is located on the x-axis, at x = 10 cm.

There is only one point on the x-axis at which the net electric field equals zero. Where is that point located? Find the formula which that location (labeled by x) obeys. (All lengths are in cm.)

(a) x < 0 (b) 0 < x < 5 (c) x = 5 (d) 5 < x < 10 (e) x > 10

(a) 148 V (b) 212 V (c) 1380 V

the circuit shown, the battery voltage ε = 9 volts, and the capacitors C_{1} = 6 μF, C_{2} = 27 μF and C_{4} = 15 μF.

As of now, we are not told the value of C_{3}. Nevertheless, what can we say about Q_{2} (the charge on C_{2}) versus Q_{3} (the charge on C_{3})?

(a) Q_{2} is greater than Q_{3}. (b) Q_{2} is not greater than Q_{3}. (c) We need to know the value of C_{3} before we can answer this question.

(a) 54 μC (b) 68 μC (c) 144 μC (d) 188 μC (e) 297 μC

(a) 54 μC (b) 81 μC (c) 146 μC

(a) C_{A} = C_{B} (b) C_{A} > C_{B} (c) C_{A} < C_{B}

As the plates of the capacitor are pulled apart, what happens to the hanging gold strips?

(a) They collapse (fall together). (b) They fly apart.

(a) 3 Ω (b) 4.8 Ω (c) 7.2 Ω (d) 12 Ω (e) 20 Ω

In this circuit, you are given:

R_{1} = 15 Ω R_{2} = 20 Ω R_{3} = 20 Ω R_{4} = 5 Ω R_{5} = 35 Ω

You are also told that a current I_{1} = 0.4 A flows downward through R_{1}.

Calculate the battery voltage.

(a) 2 V (b) 3 V (c) 4 V (d) 5 V (e) 6 V

(a) 7.5 Ω (b) 22 Ω (c) 25 Ω (d) 30 Ω (e) 95 Ω

(a) 1 V (b) 4 V (c) 8 V

These three questions refer to three different experiments conducted with the circuit shown. In each, assume the capacitor starts uncharged.

Close both switches at t = 0. After a long time has elapsed, what is the current through the 12 Ω resistor?

(a) 0 (b) 0.5 A (c) 1.25 A

(a) 0 (b) 0.5 A (c) 0.83 A (d) 1.25 A (e) 2.08 A

(a) 7.05 μC (b) 6.10 μC (c) 4.14 μC (d) 3.15 μC (e) 2.10 μC

True or false: resistors R_{2} and R_{3} can be combined into a single resistor because they are in series.

(T) True (F) False

(a) I_{4} = I_{3} + I_{2} (b) I_{1} + I_{2} = I_{3} + I_{4} (c) I_{1} + I_{2} = I_{4} - I_{3}

(a) -V_{2} - I_{2}R_{4} + I_{3}R_{5} = 0 (b) I_{3}R_{5} + I_{4}R_{6} - V_{3} = 0 (c) V_{3} + I_{4}R_{6} - V_{2} - I_{2}R_{4} = 0