Explanation

(a) The circuit diagram is follows:
For 1$\Omega$ resistors in parallel, the resultant resistance is
$\frac{1}{R} = \frac{1}{R_{1}} + \frac{1}{R_{2}}$
Where, $R_{1} = R_{2} = 1\Omega$
$\therefore\ \ \ \frac{1}{R} = \frac{1}{1} + \frac{1}{1} = \frac{2}{1}$
$\Longrightarrow \ \ R = 0.5\Omega$
This 0.5$\Omega$ resistor is connected in series with1.5$\Omega$ resistor.
Hence, equivalent resistance is
R’=0.5+1.5=2$\Omega$
From Ohm’s law, current flowing in the circuit is given by
$\ \ \ \ \ V = iR$
$\Longrightarrow i = \frac{V}{R} = \frac{10}{2} = 5A$