Engineering :: Metallurgy
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31. |
Percentage of carbon is least in case of |
A. |
Pig iron |
B. |
Cast iron |
C. |
Malleable iron |
D. |
Wrought iron |
E. |
Steel |
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Answer: Option D
Explanation:
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32. |
The process used for making steel is |
A. |
Bessemer converter |
B. |
Open hearth |
C. |
Electric arc |
D. |
High frequency heating |
E. |
Any of the above |
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Answer: Option E
Explanation:
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33. |
In high frequency heating of steel, the heat is generated primarily due to |
A. |
Eddy currents |
B. |
Stray magnetic fields |
C. |
High voltage |
D. |
High power |
E. |
High resistance of contact surface |
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Answer: Option A
Explanation:
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34. |
Eddy currents |
A. |
Increase with frequency |
B. |
Increase with square of frequency |
C. |
Increase with cube of frequency |
D. |
Increase with fourth power of frequency |
E. |
Increase as inverse of frequency |
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Answer: Option B
Explanation:
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35. |
In eddy current heating of steel, if the depth of heating is to be increased |
A. |
Frequency must be high |
B. |
Frequency must be low |
C. |
Some resisting material must be applied on the surface of article to be heated |
D. |
Time of heating should be high |
E. |
Voltage should be high |
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Answer: Option B
Explanation:
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36. |
Brinell hardness of nitrided surface may be of the order of |
A. |
100 |
B. |
150 to 200 |
C. |
200 to 250 |
D. |
300 to 450 |
E. |
More than 600 |
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Answer: Option E
Explanation:
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37. |
The chemical formula of cementite is |
Answer: Option B
Explanation:
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38. |
Which of the following is not true for cementite? |
A. |
It is hard |
B. |
It is brittle |
C. |
It is brilliantly white |
D. |
It is found is steels |
E. |
It has low melting point |
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Answer: Option E
Explanation:
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39. |
A fine grained steel will have the number of grains per square centimeter as |
A. |
3 to 16 |
B. |
16 to 56 |
C. |
56 to 100 |
D. |
100 to 150 |
E. |
150 to 1000 |
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Answer: Option A
Explanation:
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40. |
High carbon steels intended to be quenched in water should have manganese percentage less than |
A. |
2 percent |
B. |
1.5 percent |
C. |
1 percent |
D. |
0.5 percent |
E. |
No manganese percent |
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Answer: Option D
Explanation:
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