Where the values kA and kI can be freely chosen. (a) Find the characteristic equation of this system. (b) For what values of kA and kI will the system be stable? (c) If kA = 10 and kI = 100 how many roots of the characteristic equation will be positive? How do you know? (d) If kI = 100 for what values of kA will the system be marginally stable? Find the root(s) of the characteristic equation associated with this stability.

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk

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?