When the winding c-d of the single-phase, 50 Hz, two winding transformer is supplied from an AC current source of frequency 50 Hz, the rated voltage of 200 V (rms), 50 Hz is obtained at the open-circuited terminals a-b. The cross sectional area of the core is 5000 mm$$^2$$ and the average core length traversed by the mutual flux is 500 mm. The maximum allowable flux density in the core is $$B_{max} = 1$$ Wb/m$$^2$$ and the relative permeability of the core material is 5000. The leakage impedance of the winding a-b and winding c-d at 50 Hz are (5 + j100$$\pi$$ $$\times$$ 0.16) $$\Omega$$ and (11.25 + j100$$\pi$$ $$\times$$ 0.36) $$\Omega$$, respectively. Considering the magnetizing characteristics to be linear and neglecting core loss, the self-inductance of the winding a-b in millihenry is ___________ (Round off to 1 decimal place).
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