Answer:
1. High friction
2. High extrusion temperature
Explanation:
Surface cracking on extruded products are defects or breakage on the surface of the extruded parts. Such cracks are inter granular.
Surface cracking defects arises from very high work piece temperature that develops cracks on the surface of the work piece. Surface cracking appears when the extrusion speed is very high, that results in high strain rates and generates heat.
Other factors include very high friction that contributes to surface cracking an d chilling of the surface of high temperature billets.
Answer:

Explanation:
Availability:
It define as the probability of system which perform desired task before showing any failure .
The availability can be define as follows

Or we can say that

Availability can also be express as

Where MTBF is the mean time between two failure.
MTTR is the mean time to repair.
Answer:
The answer is "
"
Explanation:
Air flowing into the
Flow rate of the mass 
inlet temperature 
Pipeline
Its air is modelled as an ideal gas Apply the ideum gas rule to the air to calcule the basic volume v:




Answer:
thrust washer
can be used to eliminate rubbing friction of wheel touching frame
Answer:
(d) a and c are correct
Explanation:
METALS : Metal are those materials which has very high ductility, high modulus of elasticity, good thermal and electrical conductivity
for example : iron, gold ,silver, copper
ALLOYS: Alloys are those materials which are made up of combining of two or more than two metals these also have good thermal and electrical conductivity and me liable property
for example ; bronze and brass
so from above discussion it is clear that option (d) will be the correct option