$\text { wires }=\frac{\mu_0 i_1 i_2}{2 \pi d }$
$\frac{ F _1}{ F _2}=\frac{\frac{\mu_0(10)^2}{2 \pi(5\,cm )}}{\frac{\mu_0(20)^2}{2 \pi\left(\frac{5 cm }{2}\right)}}=\frac{1}{8}$
$\Rightarrow F_2=8 F_1$
$(a)$ Shape of loop
$(b)$ Area of loop.
$(c)$ Current in loop
$(d)$ External magnetic field.

($A$) The maximum voltage range is obtained when all the components are connected in series
($B$) The maximum voltage range is obtained when the two resistors and one galvanometer are connected in series, and the second galvanometer is connected in parallel to the first galvanometer
($C$) The maximum current range is obtained when all the components are connected in parallel
($D$) The maximum current range is obtained when the two galvanometers are connected in series and the combination is connected in parallel with both the resistors