Question Set 2

Question No. 1

What are the principal constituents of brass?

Answer:

Principal constituents of brass are copper and zinc.

Question No. 2

What is Curie point?

Answer:

Curie point is the temperature at which ferromagnetic materials can no longer be magnetized by outside forces.

Question No. 3

By which instruments the shear stress in fluids can be measured directly?

Answer:

By Stanton tube or Preston tube.

Question No. 4

Explain the difference between the points of inflexion and contra-flexure.

Answer:

At points of inflexion in a loaded beam the bending moment is zero and at points of contra-flexure in loaded beam the bending moment changes sign from increasing to decreasing.

Question No. 5

What is the difference between proof resilience and modulus of resilience?

Answer:

Proof resilience is the maximum strain energy that can be stored in a material without permanent deformation. Modulus of resilience is the maximum strain energy stored in a material per unit volume.

Question No. 6

What do you understand by critical points in iron, iron-carbide diagram?

Answer:

The temperatures at which the phase changes occur are called critical points (or temperatures).

Question No. 7

Define buckling factor.

Answer:

It is the ratio of the equivalent length of column to the minimum radius of gyration.

Question No. 8

State the difference between Anti Friction Bearing and Journal Bearing.

Answer:

Generally, journal bearings have higher friction force, consume higher energy and release more heat, but they have larger contact surface, so normally used in low speed high load applications. In anti friction bearings friction is less. One object just rolls over each other.

Question No. 9

How to Find, Ductile-Brittle Transition Temperature in Metals?

Answer:

The point at which the fracture energy passes below a pre-determined point for a standard Impact tests. DBTT is important since, once a material is cooled below the DBTT, it has a much greater tendency to shatter on impact instead of bending or deforming.

Question No. 10

What is the difference between P-11 and P-12 Pipes?

Answer:

P-11 the chromium molybdenum composition that is 1% of chromium and 1/4% of molybdenum P-12 the chromium molybdenum composition that is 1% of chromium and 2% of molybdenum.