There are preemptive and non-preemptive approaches to handle critical section in operating system. As non-preemptive approaches doesn’t face problem of race conditions, explain in detail why we still use preemptive approaches to handle critical section.

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? explain.

Air flows over a heated plate àt a velocity of 50m/s. the local skin factor coefficient at a point on a plate is 0.004. estimate the local heat transfer coefficient at this point.the following property data for air are given: density = 0.88kg/m3 , viscosity 2.286 x 10 ^-5 kgm/s , k = 0.035w/mk ,cp = 1.001kj/kgk. use colburn reynolds analogy.

The proportional limit is always greater than the yield strength for a material. a)-trune b)- false