Question

Find equivalent resistance between a and b​

Answer 1

Explanation:

In the given circuit ignoring topmost & bottommost R as it will be of no use.

Hence in upper & lower delta,

Req = (R + R) || R

= {(2R × R) / (2R + R)}

= (2/3)R.

Also in left & right combination of resistors, Req is given by R||R||R = (R/3) hence circuit can be drawn as

∴ RAB = {(2/3) R + (R/3)} || {(2/3)R + (R/3)}

= R || R

= (R/2)