This set of Engineering Materials Science "Multiple Choice Questions & Answers" are based on "PHASE TRANSFORMATION"
PHASE TRANSFORMATION
Multiple Choice Questions (MCQ)
Hello reader, here you can find some MCQ with answers. But before reading this I will suggest you take a practice test on these questions given below. so you can understand your strength on this topic.
Click here to go Practice Test section on this topic namely Phase Transformation.
But if you want to read this topic first and then practice it then read it carefully. The Multiple Choice Questions (MCQ) based on Phase Transformation are given below:
PART - I
1) Below the critical radius the tiny particles are _______ and are called _______
Correct Answer is "C"
Below the critical radius, the tiny particles are unstable since the free energy value is in increasing condition and is called an embryo.
2) Both nucleation and growth require a change in free energy to be ________
Correct Answer is "B"
Both nucleation and growth require a change in free energy to be negative. Any process should be thermodynamically possible if free energy change associated with the process is negative.
3) During homogeneous nucleation, the critical size of a particle ______ with an increase in under-cooling
Correct Answer is "B"
With an increasing degree of undercooling nucleation increases and growth decreases. So the number of nucleus increases but the size of the nucleus decreases.
4) Overall transformation rate changes with temperature as follows
Correct Answer is "C"
Overall transformation rate first increases due to free energy change decreases and then decreases due to atomic mobility decreases
5) Nose of a C-curve represents
Correct Answer is "B"
The nose of a C-curve represents the Shortest time required for a specified fraction of transformation
6) For a spherical particle of radius r, the volume-to-surface area ratio is
Correct Answer is "A"
For a spherical particle of radius r, the volume-to-surface area ratio is = (4/3 πr^3)/(4πr^2 ) = r/3
7) As compared to the nucleation-rate maximum, the growth-rate maximum is at
Correct Answer is "D"
As compared to the nucleation-rate maximum, the growth-rate maximum is at a higher temperature
8) Fine grain sizes are obtained by
Correct Answer is "C"
Fine-grain sizes are obtained by fast cooling. Decreasing nucleation rate, increasing growth rate, & slow cooling are favorable for growth which gives rise to coarse grain.
9) The activation free energy of homogeneous nucleation is _____ heterogeneous nucleation
Correct Answer is "A"
The activation free energy of homogeneous nucleation is higher than heterogeneous nucleation
10) What are the characteristics of large supercooling in nucleation?
Correct Answer is "C"
Many nuclei, small crystals are the characteristics of large supercooling in nucleation
Do you read all the questions and answers given above carefully? let's make a practice on all the questions given above.
Go to: Practice Test on Phase Transformation (MCQ) Part - I
Suggested Topics:
Disclaimer:
Some of the questions given above may be similar to questions from some books and other online available sources but the answers to all the questions are genuinely made by admin@materialscienceonline.
Let me know if this post is helpful or not?
I am trying my best to gather more and more objective type questions on this site for your best practice. If you have any queries about any questions given above then don't hesitate to comment below or you can also directly contact me through materialscienceonline4u@gmail.com.
MaterialScienceOnline is made to provide you all types of chapter-wise objective (Multiple Choice, Multiple Select and Numerical) questions, answers, and explanations as well as a chapter-wise various practice tests or quiz to catalyst your competitive exam preparation. Various top-rated Material Science and Engineering pdf books are also available here.
Thank you for visiting this site. If you think this post is helpful then share this post as well as this website with your friends.
No comments:
Post a Comment
Let me know about this post..