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 123. The exam period was 90 minutes; the average score was 89.0; the median score was 90. Click here to see page1 page2 of the formula sheet that came with the exam.

A series RLC circuit with L = 25 mH, C = 0.8 μF and R = 7 Ω is driven by a generator with a maximum emf of 12 V and a variable angular frequency ω.

Find I_{max} at resonance.

(a) I_{max} = 0 A (b) I_{max} = 1.7 A (c) I_{max} = 3.8 A (d) I_{max} = 4.3 A (e) I_{max} = 6.9 A

(a) leads the generator voltage by 90°. (b) lags the generator voltage by 90°. (c) is in phase with the generator voltage.

(a) increase. (b) decrease. (c) stay the same.

(a) Z = 7 Ω (b) Z = 12.3 Ω (c) Z = 27.1 Ω (d) Z = 44.3 Ω (e) Z = 172 Ω

(a) 11.3°. (b) 23.4°. (c) 80.9°. (d) 90°. (e) not enough information to determine

(a) (b) (c)

The current in a series RLC circuit leads the generator voltage by φ = 30°. The circuit, containing an inductor L = 400 mH and a resistor R = 50 Ω, is driven by a generator operating at ω = 100 rad/s with a maximum emf of 10 V. The capacitance is unknown.

The value of the capacitance C is

(a) C = 32 μF. (b) C = 145 μF. (c) C = 580 μF. (d) C = 900 μF. (e) C = 1.18 mF.

(a) U_{C} = U_{C,max} sin^{2}φ (b) U_{C} = U_{C,max} sinφ (c) U_{C} = U_{C,max} tan^{2}φ (d) U_{C} = U_{C,max} tanφ (e) U_{C} = U_{C,max} cos^{2}φ

The plot below depicts the electric field component of a linearly polarized, electromagnetic plane wave traveling through vacuum. E(r,t) propagates in the negative z-direction and toward an observer located at z = 0. (Note that x is directed into the page.)

The magnetic field associated with this wave may have the form (assuming k and ω have their usual definitions):

(a) B(r,t) = xB_{max}sin(kz-ωt) (b) B(r,t) = xB_{max}sin(kz+ωt) (c) B(r,t) = zB_{max}sin(kz-ωt) (d) B(r,t) = -xB_{max}sin(kz+ωt) (e) B(r,t) = -xB_{max}sin(kz-ωt)

(a) E_{max} = 0.51 V/m (b) E_{max} = 0.89 V/m (c) E_{max} = 4.9 V/m (d) E_{max} = 8.3 V/m (e) E_{max} = 15.5 V/m

(a) λ_{earth} = 64 nm (b) λ_{earth} = 445 nm (c) λ_{earth} = 450 nm (d) λ_{earth} = 455 nm (e) λ_{earth} = 3150 nm

(a) N_{s} = 25 (b) N_{s} = 75 (c) N_{s} = 400

As shown at right below, a laser is directed into a water tank (filled with water having an index of refraction n_{2} at the laser wavelength) at an angle θ_{1} from the vertical and strikes the bottom of the tank at point A, a horizontal distance r away from B, the spot directly underneath the place where the light enters the water.

The distance r is:

(a) (b) (c) (d) (e)

(a) the same for a green and a red laser. (b) smaller for a red laser than for a green laser. (c) smaller for a green laser than for a red laser.

The ratio of the final intensity I_{f} of the transmitted light to the intensity I_{i} of the incident light is:

(a) I_{f} / I_{i} = 0 (b) I_{f} / I_{i} = 2.1 × 10^{-14} (c) I_{f} / I_{i} = 0.53 (d) I_{f} / I_{i} = 0.76 (e) I_{f} / I_{i} = 1

(a) I_{H} > I_{C} > I_{V} (b) I_{H} = I_{C} > I_{V} (c) I_{H} = I_{C} = I_{V} (d) I_{H} < I_{V} < I_{C} (e) I_{H} < I_{C} < I_{V}

(a) have a vertical polarization direction. (b) have a polarization dependent on the direction of the incident polarization direction. (c) be unpolarized.

The switch has been in position a for a long time, completely charging the capacitor. At t = 0 the switch is thrown to position b. The values of the battery voltage, V, and the capacitance, C are given; the maximum current I_{max} is measured after the switch is thrown to position b.

Find the inductance L.

An object (bold arrow) is located at a distance of 3f / 2 (i.e. at x = -3f / 2) in front of a diverging lens as shown in the figure. Note that f is positive, so the focal length of this lens is -f.

What is the location x_{i} of the image?

(a) x_{i} = -3f / 5 (b) x_{i} = -3f / 2 (c) x_{i} = 3f / 2 (d) x_{i} = f / 2 (e) x_{i} = f / 5

(a) The image is real and inverted. (b) The image is virtual and inverted. (c) The image is real and upright. (d) The image is virtual and upright. (e) There is no image formed.

(a) M = 0 (b) M = 1/2 (c) M = 1

A constant current I is supplied for a brief time to charge a parallel plate capacitor. The capacitor has circular plates of radius R with a gap d (d << R). Point 1 is at a distance R + d from the wire, and point 2 is at a distance R + d from the center of the capacitor.

During the time interval that the constant current I is flowing through the capacitor, the magnetic field at point 2, B_{2} is:

(a) B_{2} > B_{1} (b) B_{2} = B_{1} (c) 0 < B_{2} < B_{1} (d) B_{2} = 0 (e) not enough information to tell

(a) the electric flux and the magnetic field between the plates are both zero. (b) the electric flux between the plates is zero and the magnetic field between the plates is non-zero. (c) the electric flux between the plates is non-zero and the magnetic field between the plates is zero.