Answer:
Planned maintenance refers to any scheduled activity carried out to check a machine is working ok and diagnose procedures to fix it if need it. On the other hand, predictive mainteance is all the techniques which help to define if a machine requires or not maintenance activities so far.
Explanation:
Planned maintenance is based on preventive routines to ensure a machine is working in acceptable conditions and at the same time prevent them to change to risky values performing acticities like parts replacement, cleaning, etc. The key of this maintenance is schedule, that is to say, is a maintenance that has to be carried out constantly each certain time. Predictive maintenance is different because it is used to define if a machie needs any kind of inspection or if, on the contrary, the machine can continue operating without any intervention. The good point about predictive maintenance is the capability of telling when a maintenance is required and when is no necessarily required which is ideal to save costs.
A8 is the answer because yea and because I am a teacher
Answer:
(a) Precipitation hardening
(1) The strengthening mechanism involves the hindering of dislocation motion by precipitates/particles.
(2) The hardening/strengthening effect is not retained at elevated temperatures for this process.
(4) The strength is developed by a heat treatment.
(b) Dispersion strengthening
(1) The strengthening mechanism involves the hindering of dislocation motion by precipitates/particles.
(3) The hardening/strengthening effect is retained at elevated temperatures for this process.
(5) The strength is developed without a heat treatment.
Answer:
The correct answer is A : Orientation dependence of normal and shear stresses at a point in mechanical members
Explanation:
Since we know that in a general element of any loaded object the normal and shearing stresses vary in the whole body which can be mathematically represented as

And 
Mohr's circle is the graphical representation of the variation represented by the above 2 formulae in the general oriented element of a body that is under stresses.
The Mohr circle is graphically displayed in the attached figure.