Determine the equivalent resistance of networks shown in Fig.

Explanation

(a) The given network is a series combination of 4 equal units. Each unit has 4 resistances in which 2 resistance (`1Omega` each in series) are in parallel with 2 other resistances
(`2 Omega` each in series)
`:.` Effective resistance of two resistance (each of `1 Omega`) in series `= 1 + 1 = 2 Omega`
Effective Resistance of two resistance (each of `2 Omega`) in series `= 2 + 2 = 4 Omega`
If R is the resistance of one unit of resistance them
`(1)/(R_(P)) = (1)/(2) + (1)/(4) = (3)/(4)` or `R_(P) = (4)/(3) Omega`.
`:.` Equivalent resistance in network `= 4 R_(P) = 4 xx (4 Omega)/(3) = (16 Omega)/(3)`
(b) Total resistances each of the value of R are connected in series. Their effective resistance = 5R