Q. Find the equivalent resistance between points A and B in the following circuits:

(a) 5R/4

(b) 6R/4

(c) 8R/5

(d) 9R/5

Ans: (a)

Sol: The circuit is symmetry about perpendicular bisector of AB , hence remove this bisector and redraw the circuit .

Now 4R and 2R becomes in parallel