List of top Fluid Mechanics and Thermal Sciences Questions on Thermal boundary layer asked in GATE ME

Consider a hydrodynamically fully developed laminar flow through a circular pipe with the flow along the axis (i.e., z direction). In the following statements, T is the temperature of the fluid, Tw is the wall temperature and Tm is the bulk mean temperature of the fluid. Which one of the following statements is TRUE?
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 meter. 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 \( \left| \frac{dT}{dy} \right| \) within the slab at \( y = 0 \) is \(\underline{\hspace{1cm}}\) K/m (round off to the nearest integer).