Ahot oil at 150°c is flowing through a tube of inner radius 20 mm made of a steel alloy of thickness 2 mm and the outer surface of the tube is exposed to ambient air at 30 ° c. the he k - 14 w/m. k) at transfer coeff icient between the inner surface of tube and oil is 1000 w/m2 k and that between the outer surface of tube and ambient air is 10 w/m'.k. the rate of heat transfer per unit length is close to:

Line joining liquid phase with liquid and solid phase mixture is known as: a) liquidus b) solidus c) tie line d) none of the mentioned

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.