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 119. The exam period was 90 minutes. The mean score was 98.5; the median was 103. Click here to see page1 page2 of the formula sheet that came with the exam.

(a) 26.5 A (b) 33.3 A (c) 45.1 A (d) 56.7 A (e) 67.7 A

(a) 101 Ω (b) 155 Ω (c) 198 Ω (d) 218 Ω (e) 333 Ω

The aliens set their receiver to listen for signals at a frequency of 10 MHz. To what value should Lisa tune the inductor so that the circuit inside her radio is resonant at the same frequency?

(a) 2.53 × 10^{-9} H (b) 3.85 × 10^{-9} H (c) 4.51 × 10^{-9} H (d) 5.89 × 10^{-9} H (e) 7.70 × 10^{-9} H

(a) 0.111 W (b) 0.250 W (c) 0.458 W (d) 0.611 W (e) 0.999 W

(a) 0.0102 V (b) 0.0111 V (c) 0.0159 V (d) 0.153 V (e) 0.557 V

(a) at a minimum. (b) neither at a maximum or a minimum. (c) at a maximum.

(a) decreases. (b) stays the same. (c) increases.

(a) decreases by half. (b) stays the same. (c) quadruples (increases by 4x).

(a) parallel (b) series

(a) (b) (c)

(a) 50 million kilometers (b) 100 million kilometers (c) 150 million kilometers

Two particles, A (m_{A}=1.7 ×10^{-27} kg , Q_{A}= 1.6 × 10^{-19 }C ) and B (m_{B}= 3.4 × 10^{-27} kg , Q_{B}= -3.2 × 10^{-19 }C ) enter a box with uniform magnetic field B= 6 T. Particle A enters with velocity v_{ }=10^{8} m/s and follows trajectory A.

What is the direction of the magnetic field inside the box?

(a) into the page (b) out of the page (c) up (d) down (e) right

(a) trajectory 1 (b) trajectory 2 (c) trajectory 3

(a) L = 0.115 m (b) L = 0.354 m (c) L = 0.637 m (d) L = 1.43 m (e) L = 1.75 m

A rectangular loop of wire is located near a long, straight wire that carries a current of 6 A flowing to the right (see the figure). The current in the loop I_{loop} = 8 A is flowing clockwise.

The loop of wire is attracted to the long straight wire.

(T) True (F) False

(a) |F| = 0 N (b) |F| = 1.44 × 10^{-5} N (c) |F| = 6.89 × 10^{-5} N (d) |F| = 3.65 × 10^{-4} N (e) |F| = 8.72 × 10^{-4} N

Two fixed conductors are connected by a resistor R = 20 Ω . The two fixed conductors are separated by L = 2.5 m and lie vertically, parallel to the gravitational field (g = 9.8 m/s^{2}). A moving conductor of mass m slides on them (without friction) falling at a constant speed v = 6 m/s. Out of the page is a magnetic field (shown by the black dots in the figure) with a magnitude of 5^{ }T.

In which direction does the current flow through the moving conductor?

(a) to the right (b) to the left

(a) 1.37 A (b) 2.44 A (c) 3.75 A (d) 4.98 A (e) 5.39 A

In the figure is shown a square loop (L=2 m) of wire in edge view, which is free to rotate around an axis O (perpendicular to the page). The loop consists of 12 loops of wire and the normal to the loops forms an angle of 30° to the vertical. An external battery (not shown) causes a current I=6 amps to flow around the loop. The external magnetic field directed down (B=6 T) creates a clockwise torque on the current loop.

What is the direction of the current in side A (which runs normal to the page)?

(a) into the page (b) out of the page

(a) 348 N m (b) 487 N m (c) 620 N m (d) 735 N m (e) 864 N m

This figure illustrates a plane electromagnetic wave.

Compare the z-component of the electric field at the points a, b and c.

(a) +x-direction (b) +y-direction (c) +z-direction

The figure below shows wires wrapped around an iron core. Coil A has 10 turns, and coil B has 5 turns. This serves as an ideal transformer between an AC generator and a resistor. The resistance R = 9 Ω. The average power dissipated in the resistor is P = 90 W.

What is the maximum current through the resistor?

(a) 2.52 A (b) 4.47 A (c) 6.95 A (d) 8.41 A (e) 10 A

(a) 49.2 V (b) 56.9 V (c) 63.3 V (d) 78.5 V (e) 90 V

(a) less than 10 turns (b) equal to 10 turns (c) more than 10 turns

A loop with 200 turns of wire is placed into a constant horizontal magnetic field B, as shown in the figure below. It is turned at a steady rate of 500 rad/sec and generates a maximum voltage of 160 V. The loop has a total resistance of 90 ohms. The loop rotates in the direction indicated by the curved arrow.

What is the magnitude of the magnetic field B?

(a) 0.0231 T (b) 0.0424 T (c) 0.0625 T (d) 0.0891 T (e) 0.102 T

(a) smaller than 160 V (b) equal to 160 V (c) larger than 160 V

(a) smaller than 160 V. (b) equal to 160 V. (c) larger than 160 V.