In the figure, battery B supplies 18 V. Find the charge on each capacitor first
ID: 1282511 • Letter: I
Question
In the figure, battery B supplies 18 V. Find the charge on each capacitor first when only switch S1 is closed. Take C1 = 1.6 uF, C2 = 2.6 uF, C3 =3.7 uF, and C4 = 4.0 uF.
Q1? Q2? Q3? Q4?
Find the charge on each capacitor later when switch S2 is also closed. Q1? Q2? Q3? Q4?
In the figure, battery B supplies 18 V. Find the charge on each capacitor first when only switch S1 is closed. Take C1 = 1.6 uF, C2 = 2.6 uF, C3 =3.7 uF, and C4 = 4.0 uF. Q1? Q2? Q3? Q4? Find the charge on each capacitor later when switch S2 is also closed. Q1? Q2? Q3? Q4?Explanation / Answer
when s2 is closed
C12 = C1 + C2 = 1.6 + 2.6 = 4.2 micro F
C34 = C3 + C4 = 3.7 + 4 = 7.7 micro F
Cnet = C12*C34/(C12+C34) = 4.2*7.7/(4.2+7.7) = 2.717 micro F
Qnet = V*Cnet
= 18*2.717*10^-6
= 48.92*10^-6 C
Q1 = Qnet*C1/(C1+C2) = 48.92*10^-6*1.6/(1.6+2.6) = 18.63*10^-6 C
Q2 = Qnet*C2/(C1+C2) = 48.92*10^-6*2.6/(1.6+2.6) = 30.29*10^-6 C
Q3 = Qnet*C3/(C3+C4) = 48.92*10^-6*3.7/(3.7+4) = 23.5*10^-6 C
Q4 = Qnet*C4/(C3+C4) = 48.92*10^-6*4/(3.7+4) = 25.42*10^-6 C