Question

(a) Find the equivalent capacitance between points a and b.

(b) Calculate the charge on each capacitor if a 15 V battery isconnected across
points a and b.
the 20.0 µF capacitor
µC
the 6.00 µF capacitor
µC
the 3.00 µF capacitor
µC
capacitor C
µC

Answer 1

(a)
from the ciruit to calculate the equivalentcapacitance first we see that the capacitors
15 μF and 3 μF are in series so theirequivalent will be
(15 μF) (3 μF) / (18 μF) = 2.5μF
this is in parallel with 6 μF then
2.5 μF + 6 μF = 8.5 μF
this is in series with 20 μF capacitor
so the equivalent capacitance will be
C_eq = (8.5 μF) (20 μF) / (28.5μF)
= 5.96μF
(b)
the voltage across the 20 μF capacitor willbe
V_{20 μF} = (15) (8.5 μF) / (28.5μF)
= ....... V
the charge on the 20 μF capacitor will be
Q_{20 μF} = (20 μF) (V_20μF)
= ......... C
the voltage across the 6 μF capacitor will be
V_{6 μF} = (15) (20 μF) / (28.5μF)
= ....... V
the charge on the 6 μF capacitor will be
Q_{6 μF} = (6 μF) (V_6μF)
= ......... C
the voltage across the 15 μF capacitor willbe
V_{15 μF} = (V_{6 μF}) (3μF) / (18 μF)
= ....... V
the charge on the 15 μF capacitor will be
Q_{15 μF} = (15 μF) (V_15μF)
= ......... C
the voltage across the 3 μF capacitor will be
V_{3 μF} = (V_{6 μF}) (15μF) / (18 μF)
= ....... V
the charge on the 3 μF capacitor will be
Q_{3 μF} = (3 μF) (V_3μF)
= ......... C