Concept:Redraw the network using node analysis and simplify parallel and series combinations step by step.
Explanation:Label the top junction as
B, the left lower junction as
A, and the right lower junction as
C.
The two
3C capacitors are both connected between
A and
B, so they are in parallel.
Their equivalent is
CAB​=3C+3C=6C.
The
1C capacitor and the right-side
2C capacitor are both between
B and
C, so they are also in parallel.
Their equivalent is
CBC​=1C+2C=3C.
Now
CAB​ and
CBC​ are connected in series between
A and
C.
The series equivalent is
6C+3C6C×3C​=2C.
This
2C series combination is in parallel with the middle
2C capacitor.
Thus total equivalent capacitance is
Ceq​=2C+2C=4C.
Energy stored is
U=21​Ceq​V2.
Substituting
Ceq​=4C, we get
U=21​(4C)V2=2CV2.
Answer:Equivalent capacitance is
4C and energy stored is
2CV2, which matches option A.