A ferromagnetic material $($Fig$.$ C$)$ with a square cross$-$sectional area of $16c{m}^2$ has a relative permeability of $1000.$ The number of turns in the coil is $1000.$ The magnetic flux established in the core $($Fig$.$ C$)$ is $6\mathrm{.}4mWb.$ The above core is cut into equal halves and the one with the coil is extended with the same material as shown in Fig. D$.$ If the outer $($maximum$)$ circumference of the core $($Fig$.$ C$)$ is $95\mathrm{.}0$ cm$,$ the new current in the coil required $($Fig$.$ D$)$ to produce the same magnetic flux of $6\mathrm{.}4mWb$ without changing the number of turns $($the turns being same as of Fig. C$,$ i$.$e$.,1000)$ is$\_\_$

C

Fig.

Fig.

D

A$.$