Curves in the graph shown in figure give, as functions of radius distance $\mathrm{r},$ the magnitude $\mathrm{B}$ of the magnetic field inside and outside four long wires $\mathrm{a}, \mathrm{b}, \mathrm{c}$and $\mathrm{d},$ carrying currents that are uniformly distributed across the cross-sections of the wires. Overlapping portions of the plots are indicated by double labels.

Which wire has the largest radius?

The below figure shows two closed paths wrapped around two conducting loops carrying currents $i_1=5.0 \mathrm{A}$ and $i_2=3.0 \mathrm{A}.$ What is the value of the integral $\oint \overrightarrow{\mathrm{B}}·\mathrm{d}\overrightarrow{\mathrm{s}}$ for
(a) path $1$ and (b) path $2$?

Each of the eight conductors in the below figure carries $2.0 \mathrm{A}$ of current into or out of the page. Two paths are indicated for the line integral $\oint \overrightarrow{\mathrm{B}}·d\overrightarrow{\mathrm{s}}.$ What is the value of the integral for$\left(a\right)$ path $1$ and$\left(b\right)$ path $2$?

A toroid having a square cross-section, $5.00 \mathrm{cm}$ on a side, and an inner radius of $19.0 \mathrm{cm}$ has $460$ turns and carries a current of $0.400 \mathrm{A}$ . (It is made up of a square solenoid-instead of round one as in figure bent into a doughnut shape). What is the magnetic field inside the toroid at (a) the inner radius and

(b) the outer radius?