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= 10 mu F + 20 mu F + 30 mu F`
Thus, the circuit can be shown like this . Now, the capacitor 15 `muF` 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 `