1. Brinell hardness test has a scale range of ________
a) 0 to 10
b) 100 to 200
c) 0 to 1000
d) 0 to 3000
Explanation: Brinell hardness test has a scale range of 0 to 3000. Brinell hardness number of soft irons is ranges from 67 to 500.
2. Rockwell hardness test has a scale range of _________
a) 0 to 10
b) 100 to 200
c) 0 to 1000
d) 0 to 3000
Explanation: Rockwell hardness test has a scale range of 0 to 1000. It is used to measure the hardness of a specimen
3. Vickers hardness test has a scale range of _____________
a) 0 to 10
b) 100 to 200
c) 0 to 1000
d) 0 to 3000
Explanation: Vickers hardness test has a scale range of 0 to 3000. It is used to measure the hardness of a specimen.
4.Brinell Hardness Number (BHN) for soft iron is between _____________
a) 1000-2000
b) 227-857
c) 67-500
d) 0-10
Explanation: Brinell hardness number (BHN) of soft iron ranges from 67 to 500.
5. What is first step involved in the process of preparing test sample for microstructural examination?
a) Rough polishing
b) Fine grinding
c) Fine polishing
d) Etching
Explanation: Fine grinding involves the use of abrasive silicon carbide, to get a flat surface, that is nearly free of the disturbed or deformed scratches which were introduced in the previous sample preparation step.
6. Which of the following compound is used for fine polishing?
a) Aluminum oxide
b) Nitric oxide
c) Silicon carbide
d) Iron oxide
Explanation: Powder form of aluminum oxide is used for fine polishing process. It is surface treatment process.
7. Etching of specimen is done to achieve ___________
a) Visible grain boundary
b) Invisible grain boundary
c) Toughness
d) Hardness
Explanation: Etching is done to obtain visible grain boundary. It is a surface treatment process.
8. What is the average grain diameter (in mm) for the grain size ASTM grain size 12?
a) .0066
b) .0078
c) .0021
d) .0056
Explanation: According to ASTM standard E1112, ”standard test methods for determining average grain size”:
n = 2G-1, where ‘G’ is the grain size number and ‘n’ represents the average number of grains per square inch at a magnification of 100X. Upon calculations one can deduce that:
Average Grain diameter (d, in mm) = \(\frac{1}{\sqrt{\frac{n×10^4}{645}}}\)
Given ASTM grain size 12, thus, n = 212-1 = 211 = 2048
Therefore, average grain diameter = \(\frac{1}{\sqrt{\frac{2048×10^4}{645}}}\) = 0.0056 mm.
9. Equipment used for inspection of inside portion of hollow chamber or narrow tube is known as ___________
a) Endoscope
b) Telescope
c) Borescope
d) Flexiscope
Explanation: Borescope is used for visual of inside portion of the hollow chamber.
10. What is the value of average number of grains in per square inch for ASTM 11?
a) 2048
b) 1024
c) 6
d) 5
Explanation: According to ASTM standard E1112, ”standard test methods for determining average grain size”:
n = 2G-1, where ‘G’ is the grain size number and ‘n’ represents the average number of grains per square inch at a magnification of 100X.
Given ASTM grain size 12, thus, n = 211-1 = 210 = 1024.