In the arrangement shown find the equivalent capacitance between A and B.

Strategy : First mark different junctions (nodes ) in the circuit. A node is a point where more than two wires are connected.

Explanation

As we can clearly see that capacitors `10 mu` F and `20 mu` F are connected between same points C and B (Parallel combination )

`:.` They can be replaced by a single capacitor of capacitance given by
`C=10mu F +20 muF= 30 mu F`
Thus the circuit can be shown like this Now the capacitors 15 `mu` F and `30 mu` F are arranged in a row ( series combination ).
`:. ` The equivalent capacitance is given by C such that `(1)/(C ) = (1)/(15)+(1)/(30) "or" C = 10 mu` F