The brittle nature of some polymers at room temperature can be attributed to: a. dislocation entanglements. b. weakening of covalent bonds in polymeric chain. c. presence of van der waals bonds linking the chains. d. atoms having similar electronegativities in the chain.

On a average work day more than work place firs are reorted

The drive force for diffusion is 7 fick's first law can be used to solve the non-steady state diffusion. a)-true b)-false

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?