Consider the system of capacitors shown in the figure below ( C 1 = 4.00 µF, C 2
ID: 1395140 • Letter: C
Question
Consider the system of capacitors shown in the figure below (C1 = 4.00 µF, C2 = 3.00 µF).
(a) Find the equivalent capacitance of the system.
______________µF
(b) Find the charge on each capacitor.
______________µC (on C1)
______________µC (on C2)
______________µC (on the 6.00 µF capacitor)
______________µC (on the 2.00 µF capacitor)
(c) Find the potential difference across each capacitor.
___________V (across C1)
___________V (across C2)
___________V (across the 6.00 µF capacitor)
___________V (across the 2.00 µF capacitor)
(d) Find the total energy stored by the group.
___________mJ
Explanation / Answer
in upper row C1 and 6 are in series this is equivalent to
1/C1' = 1/C1+1/6
C1' = 2.4 micro F
same for bottom line
1/C2' = 1/C2+1/2
C2' = 1.2 micro F
now C1' and C2' are in parallel
Ceq = C1'+C2' = 2.4 + 1.2 = 3.6 micro F
b) Total charge = Qtot =Ceq*V
Qtot = 3.6microF x 90 = 324 micro C
assume Q1 will go in upper row and Q2 will go in bottom row
Qtot = Q1+Q2
charge distributed according to their ratio
and in series combination charge remain same
Q1 = 2.4/3.6 * 324 = 216 micro C
Q2 = 1.2/3.6 *324 = 108 microC
_____216_________