Why are diffracted beams formed only at incident beam angles that satisfy bragg's law, and not at other orientations? at what 20 value would the 220 peak for fcc nickel be formed if a cu kα1 x-rays beam was used?

Shafts are machine elements that are used to a) carry axial loads b) direct shear loads c) transmit power d) rotate at constant speed e) none of the above circular and square shafts subjected to the same torque under the same circum behave a) the same way b) almost the same way