Compute the density of totally crystalline polyethylene, assuming that the equivalent of two ethylene repeat units is contained within each unit cell. a)- 99.8 g/cm3 b)- 0.998 g/cm3 c)- 0.499 g/cm3 d)- 49.9/cm3

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented

Which from the following instrument is commonly used to detect the high pitch butzing sound in bearings? [clo4] a)-digital ultrasonic meter b)-infrared camera c)-spectroscopic d)-vibrometer