1. explain why preheating the components to be welded is effective in reducing the likelihood of developing cracks
2. make a list of welding processes that are suitable for producing (a) butt joints, where the weld is in the form of a line or line segment, (b) spot welds, and (c) both butt joints and spot welds. Comment on your observations.

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.

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?

Condition monitoring is a major component of. (clo4) a)- predictive maintenance. b)-preventive maintenance c)-proactive maintenance d)-reactive maintenance.