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 124. The exam period was 90 minutes; the mean score was 99.3 the median was 103. 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) 0.38 mm (b) 0.62 mm (c) 0.79 mm (d) 1.27 mm (e) 1.62 mm

In the circuit shown below, three identical bulbs are wired to a battery.

The voltage drop across Bulb 1 is the same as the voltage drop across Bulb 3.

(T) True (F) False

(a) 2.7 A (b) 8.0 A (c) 12.0 A (d) 85.3 A (e) 384.0 A

The illustrated circuit contains two batteries, three resistors, and two switches.

At time t = t_{1} switch S_{1} is closed (so that current flows through the switch) and S_{2} is opened. What is the current I_{1}?

(a) 0.60 A (b) 1.50 A (c) 2.86 A

(a) 0.57 A (b) 0.72 A (c) 1.14 A

(a) 0.85 A (b) 0.29 A (c) 2.00 A (d) 0.57 A (e) 0.72 A

(a) 15 Ω (b) 25 Ω (c) 48 Ω (d) 72 Ω (e) 120 Ω

(a) 4.02 mF (b) 1.56 μF (c) 9.56 × 10^{-10} F

(a) The units of the electric field are equivalent to Newtons per Volt. (b) The units of capacitance are equivalent to Coulombs per Newton. (c) The units of the electrostatic potential are equivalent to Coulombs per Farad.

In the following diagram C_{1} = C_{2} = C_{3} = C_{4} = 10 μF. Initially the gap between the capacitors is empty of any material.

What is the total capacitance between points A and B?

(a) 0.014 μF (b) 0.72 μF (c) 1.2 μF (d) 2.0 μF (e) 6.0 μF

(a) 1.68 μF (b) 0.168 μF (c) 6.67 μF (d) 0.091 μF (e) 24.2 μF

(a) 3.68 J (b) 6.75 J (c) -6.75 J (d) -3.68 J (e) 1.07 J

Two charged beads, Q_{1} and Q_{2}, are placed on a long frictionless (insulating) rod. Initially they are very far apart; the bead Q_{2} is glued in place and does not move. Both beads have mass 10 g and carry charge 2 μC. Q_{1} is set in motion at a velocity v = 10 m/s towards Q_{2}.

How close does Q_{1} get to Q_{2} before reversing its direction of motion? Recall that an object’s initial kinetic energy is mv^{2}/2.

(a) 1.4 m (b) 72 mm (c) 825 μm

(a) 2.00 V (b) 6.55 V (c) 10.00 V (d) 4.00 V (e) 2.44 V

Three charges, Q_{1}, Q_{2}, and Q_{3}, are arranged on a square of side length d, as shown in the figure. Q_{1} = 5 μC, Q_{2 }= Q_{3} = -2 μC and d = 2 m.

What is the value of the electrostatic potential at point A?

(a) -8.4 kV (b) 8.4 kV (c) 2.1 kV (d) -2.1 kV (e) 4.2 kV

(a) double. (b) decrease by a factor of two. (c) not change. (d) increase by a factor of four. (e) decrease by a factor of four.

Three charges (a, b, and c) are fixed at (-4, 0), (0,4), and (+4,0) as shown in the figure: q_{a }= +2μC, q_{b}_{ }= -3μC, and q_{c}_{ }= +2μC. The grid spacing is one meter.

What is the magnitude of the force that charge b exerts on charge c?

(a) 0.03 N (b) 2.76 N (c) 1.69 mN (d) 0.32 mN (e) 0.73 N

(a) pointing up (b) pointing down (c) pointing to the left (d) pointing to the upper right (e) pointing to the lower left

(a) The magnitude of the electric field would increase by a factor of four. (b) The magnitude of the electric field would double. (c) The magnitude of the electric field would be unchanged. (d) The magnitude of the electric field would decrease by a factor of two. (e) The magnitude of the electric field would decrease by a factor four.

(a) F_{x }= 0.6325 mN and F_{y} = 1.195 mN (b) F_{x} = 1.333 mN and F_{y} = -1.23 mN (c) F_{x} = 2.03 N and F_{y} = 0.23 N (d) F_{x} = 0 and F_{y} = 0.234 mN (e) F_{x} = -30.0 mN and F_{y} = 12.0 mN

(a) A = B (b) A > B (c) A < B

A hollow conducting cylinder is held fixed between two conducting spheres that are also fixed in space. The upper sphere contains positive charge, while the lower sphere contains an equal amount of negative charge. The total charge of the conducting cylinder is zero. The cylinder is insulated from the ground.

Which figure shows the correct pattern of field lines?

(a) (b) (c)

(a) The magnitude of the electric field would increase. (b) The magnitude of the electric field would decrease. (c) The magnitude of the electric field would remain the same.

A neutral conducting sphere is placed on a frictionless plate midway between two fixed unequal point charges: q_{L} = +5μC and q_{R} = +1μC. The sphere is free to move and is insulated from the ground.

In which direction do you expect the sphere to move?

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

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

(a) 0.41 J (b) 0.081 J (c) 0.44 J (d) 1.41 J (e) 0.12 × 10^{-10} J