A network of resistor is connected to a 16 V battery with internal resistance of `1 Omega`, a shown in fig.
(a) complete the equivalent resistance of the network.

Explanation

The network is a simple series and parallel combination of resistors. First the two `4 Omega` resistors in parallel are equivalent to a resistor.
`= [(4 xx 4)//(4 + 4)]Omega = 2 Omega`
In the same, way, the `12 Omega` and `6 Omega` resistors in parallel are equivalent to a resistor of
`[(12 xx 6)//(12 + 6)] Omega = 4 Omega`
The equivalent resistance R of the network is obtained by combining these resistors (`2 Omega` and `4 Omega` with `1 Omega` in series, that is
`R = 2 Omega + 4 Omega + 1 Omega = 7 Omega`