The magnetic circuit shown below has uniform cross-sectional area and air gap of $0.2$ cm. The mean path length of the core is $40$ cm. Assume that leakage and fringing fluxes are negligible. When the core relative permeability is assumed to be infinite, the magnetic flux density computed in the air gap is $1$ tesla. With same Ampere-turns, if the core relative permeability is assumed to be $1000$ (linear), the flux density in tesla (round off to three decimal places) calculated in the air gap is _______