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Level Up Answers
Level 0
Circuit A: R_{eq}=R_1+R_2+R_3= 9 Ω V_3>V_2>V_1 I_1=I_2=I_3
Circuit B: C_{eq}=(\frac{1}{C_1}+ \frac{1}{C_2}+ \frac{1}{C_3})^{-1}= 2.3 mF Q_{1}=Q_{2}=Q_{3} V_1>V_2>V_3
Circuit C: C_{eq}=C_1+C_2+C_3 = 21 mF V_{1}=V_{2}=V_{3} Q_3>Q_2>Q_1
Circuit D: R_{eq}=(\frac{1}{R_1}+ \frac{1}{R_2}+ \frac{1}{R_3})^{-1}= 0.92 Ω V_{1}=V_{2}=V_{3} I_1>I_2>I_3
Level 1
Circuit A: R_{eq}= 350 Ω
Circuit B: R_{eq}= 400 Ω
Circuit C: C_{eq}=235 μF
Circuit D: C_{eq}=176.25 μF
Level 2
Circuit A:
Circuit B:
Circuit C
Circuit D
Level 3
Circuit A
Circuit B
Circuit C
Circuit D
Level 4
Circuit A
Given:
V_1= 9V, V_2= 6V, R=100 Ω
Simplify Circuit:
- R_1 and R_2 in series, R_1+R_2=200 Ω
Node Rule:
- I_1+I_2=I_3
Loop Rule:
- Loop A: V_1-I_1R_{12}-I_3R_3=0
- Loop B: I_3R_3-I_2R_4-V_2=0
- Loop C: V_1-I_1R_{12}-I_2R_4-V_2=0
Solution:
I_1=0.024A, I_2=0.018A, I_3=0.042A
*note can use wolfram/online/calc to evaluate I from loop AND node rule equations
Circuit B
Given:
V_1= 9V, V_2= 6V, R=100 Ω
Simplify Circuit:
- R_1 || R_2, R_{12}=50 Ω
Node Rule:
- I_1=I_2+I_3
Loop Rule:
- Loop A: V_1-I_1R_{12}-I_3R_3=0
- Loop B: V_2 -I_2R_4 +I_3R_3=0
- Loop C: V_1-I_1R_{12-V_2}-I_2R_4=0
Solution:
I_1=0.12 A, I_2=0.09A, I_3=0.03A
Circuit C
Given:
V_1= 9V, V_2= 6V, R=100 Ω
Simplify Circuit:
- R_2 and R_3 in series, R_2+R_3=200 Ω
- R_4 || R_5, R_{12}=50 Ω
Node Rule:
- I_1=I_2+I_3
Loop Rule:
- Loop A: V_1-I_1R_1+V_2-I_1R_{45}=0
- Loop B: -V_2-I_3R_{23}=0
- Loop C: V_1-I_1R_1-I_3R_{23}-I_1R_{45}=0
Solution:
I_1=0.06A, I_2=0.09A, I_3=-0.03A
Circuit D
Given:
V_1= 9V, V_2= 6V, R=100 Ω
Simplify Circuit:
- R_2 and R_3 in series, R_2+R_3=200 Ω
- R_1||R_{23}, R_{12}=66.667 Ω
Node Rule:
- I_1=I_2+I_3
Loop Rule:
- Loop A: V_1-I_1R_{123}- 0
- Loop B: I_2R_{123}-V_2-I_3R_4=0
- Loop C: V_1-V_2-I_3R_4=0
Solution:
I_1=0.165A, I_2=0.135A, I_3=0.03A
Level Bonus
(a) Initially there is current in all branches of the circuit (uncharged capacitors act like wires - current can pass through).
(b) I_i = 0.00436 A
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