GATE Mechanical Engineering (ME) 2021 Shift 2 Solved Paper

Ambient air flows over a heated slab having flat, top surface at y = 0. The local temperature (in Kelvin) profile within the thermal boundary layer is given by T(y) = 300 + 200 exp(-5y), where y is the distance measured from the slab surface in meters. If the thermal conductivity of air is 1.0 W/m.K and that of the slab is 100 W/m.K, then the magnitude of temperature gradient |dT/dy| within the slab at y = 0 is ______  K/m (round off to the nearest integer).