Seven resistances are connected The equivalent resistance of this network in between point `A` and `B` is

Options

A. `7.2 Omega`
B. `3.6 Omega`
C. `8.6 Omega`
D. `4.3 Omega`

Answer

d

Explanation

The equivalent circuit is

As `(4)/(2)= (10)/(5)`, so this network represents a balanced wheatstone bridge circuit
Therefore, `R_(AB) = ((4+2)xx(10+5))/((4+2) +(15+5)) = (6 xx 15)/(6+ 15)`
`(90)/(21) ~~ 4.3 Omega`