C2 Circuits (Chapter 18) Homework

50 points

18.1 Resistance in parallel, series and series parallel circuits.

1-8, 11, 13, 17-22, 25, 26, 29, 33, 34, 36

8: draw it! Find R parallel for the entire circuit

19: find R_parallel for 8W and for the 4W. Then, find R_series for R_p8 and R_p4. Remember, since the resistor are in parallel with each other, you must divide the ultimate current through each resistor by two since the resistors (in parallel) have the same resistance.

25: Find R_series. Then, determine I_series. Then, determine V_R3 based on I_series and 10 volts. Then, determine V_R1+R2 since V_R1+R2 + V_R3 must equal 10 volts. Finally, determine I_R1 based on V_R1+R2 and R₁

29: Find P_total by summing the watts. Recall that I = P/V and V is fixed at 120V.

33: First, know that P = V²/R. Find each individual resistance for e each bulb. Then, find equivalent resistance of the entire circuit. Realize that 15W and 40 W are in series with each other. 60W and 100 W are in parallel with each other but are in series with 15/40W. Realize I will be the same for each resistor since that are all in a series circuit so you must find I_series.

36: Break it down and decide which is in series and which is in parallel with each other.

18.2 Kirchhoff’s Rules

39, 40, 41

41: you are going from low to high potential.

18.3 RC Circuits

52--61

Answers:

2: a

4: no; only if all resistances are equal

6: 1W; it gets the most current for the same voltage

8: 10W

18: a) 11A b) 2W = 6A, 4W = 3A, 6W = 2A c) 2W = 72W, 4W = 36W, 6W = 24W d) P_total = 132W

20: 0.80W

22: 7.5W

26: a) 0.42A; 0.83A; 1.25A b) 290W; 144W; 96W

36: 8.1W

40: c

52: a

54: d

56: a) 1.5 sec b) 99.995%

58: 0.693 t

60: a) 24V b) 0 c) 4.0A