ANSWERS QUIZ 19

2, 4, 6, 14, 17 (Find the current in each resistor ), 18, 28, 38, 44, 50

2. r = 0.33 ohms

4. r = 0.068  ohms

6. (a) equivalent R = 360 ohms (b) equivalent R = 9.4 ohms

14. Each bulb has R = 450 ohms.   Fraction of total power wasted in the leads = 0.028

17. (a) 842 ohms   (b) Voltage across 470 ohm resister = 6.7 (V).   5.3 (V) is the voltage across both the 680 ohm and  820 ohm resistor, since they are in parallel.  Current through 470 ohm resistor is 1.425x10 - 2 (A). Current in 820 ohm resistor is   6.46x10 -3 (A)  .        Current in 680 ohm resistor is  7.79x10 -3 (A)  .

18. 110 ohms

28. Current in1.2 ohm resistor is  0.9217 (A), right  .   Current in 15 ohm resistor is  0.33 (A), right. .  Current in top 1.2 ohm resistor is 0.60 (A) , left .

38. V2.00 = 26.0 (V)  V 3.00 = 14.9 (V)  V 4.00 =  11.1 (V)

44.   3.3x 10 -2 J.

50. (a) C = 2.33x10 -9 F  (b)  1.42x10- 5 s