Find the equivalent resistance between `A` and `B`.
(a)
(b)

Explanation

(a) Covert delta `A X Y` into star
`x = (3 xx 3)/(3 + 3 + 3) = 1 Omega = y = z`
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(b) Convert delta `CDE` into star
`x = (R.R)/(R + R + R) = (R)/(3) = y = z`.

( c) Convert delta `AOC` and `BOD` into star,
`x = (R.R)/(R + R + R) = (R )/(3) = y = z = u = v = w`.
Or
Convert delta `COD` and `OAB` into stars
`x = (R.R)/(R + R + R) = ( R)/(3) = y = z = u = v = w`.

(d) Convert star `COAB` into delta `CAB`
`x = 6 + 4 + (6 xx 4)/(3) = 10 + 8 = 18 Omega`
`y = 4 + 3 + (4 xx 3)/(6) = 9 Omega`
`z = 6 + 3 + (6 xx 3)/(4) = (27)/(2) Omega`
Balanced Wheatstone bridge
`R_(eq) = (9 xx 18)/(9 +18) = 6 Omega`

( e) Balanced Wheatstone bridge
`R_(eq) = (9 xx 18)/(9 + 18) = 6 Omega`.

(f) Convert delta `BCD` into star
`x = (2 R xx 2 R)/(2R + 2R + 2R) = (2R)/(3) = y =z`.
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