AP DC Circuits Practice Test - LAPhysics.com

1 AP Physics - DC Circuits Practice Multiple Choice Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1. At what rate is thermal energy being generated in the 2R-resistor when = 12 V and R = ? A) 12 W B) 24 W C) W D) W E) W 2. What is the magnitude of the potential difference across the 20- resistor? A) V B) V C) 11 V D) V E) V 3. When a 20-V emf is placed across two resistors in series, a current of A is present in each of the resistors.

2 When the same emf is placed across the same two resistors in parallel, the current through the emf is 10 A. What is the magnitude of the greater of the two resistances? A) B) C) D) E) the current in the 10-V emf. A) A B) A C) A D) A E) A 5. At t = 0 the switch S is closed with the capacitor uncharged. If C = 50 F, = 20 V, and R = k , what is the charge on the capacitor when I = mA? A) 360 C B) 480 C C) 240 C D) 600 C E) 400 C 6. A capacitor in a single-loop RC circuit is charged to 85% of its final potential difference in s.

3 What is the time constant for this circuit ? A) s B) s C) s D) s E) s R1 = , R2 = , R3 = 12 , and I = A, at what rate is heat being generated in R1? A) 20 W B) 17 W C) 12 W D) 31 W E) W 8. What is the equivalent resistance between points A and B in the figure when R = 20 ? A) 77 B) 63 C) 70 D) 84 E) 140 AP Physics - DC Circuits Answer Section MULTIPLE CHOICE 1. ANS: C PTS: 1 2. ANS: B PTS: 1 3. ANS: A PTS: 1 4. ANS: A PTS: 1 5. ANS: D PTS: 1 6.

4 ANS: B PTS: 1 7. ANS: C PTS: 1 8. ANS: C PTS: 1