please give me the ans. of following mcq
A nozzle is a device which:
(A) Increase pressure & reduce kinetic energy
(B) Decreases pressure & increases kinetic energy
(C) Reduces both pressure & kinetic energy
(D) Increases both pressure & kinetic energy

Answer Posted / tushar

(b)decrease pressure &increase kinetic energy

Is This Answer Correct ?    33 Yes 2 No



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I qualified the written exam conducted by BARC and attended the interview. First let me tell you that this is the most genuine and toughest interview among all the PSUs. This is the best interview methodology that they adopt. They just ask for very basic questions of Intermediate (12th) level and want to check the basic understanding. Almost all the questions are practical questions no direct relation with the knowledge of core technical. In this way they look for the way you approach to solve a problem. Because the post they offer you is scientific officers’ post. This is a research oriented job that requires the great skills and knowledge to solve a real practical problem. So, this was a basic idea about the interview. Now let's talk about the methodology, actually they ask you 4-5 subjects in which you are more comfortable and ask the basic questions. But keep in mind that you are really comfortable with those subjects and you should be thoroughly prepared. Because they will try to divert you from your answer and will drill on topic till you surrender. But anyway you don't worry even if you are not able to solve a problem for whole but the way you approach and the basic concepts should be correct. They are generally the minimum time for interview is more than 45 minutes. Even the person they know will not be qualified; they drill him at least for 45 minutes. As the interview timing cross more than 45-60 minutes, your chance goes on increasing to get selected. Finally If they are satisfied with your performance then they give you a medical slip that insures your eligibility fir the interview. Final Result depends on the no. of posts and the merit list prepared on the basis of marks you achieved in written and interview. I wish you all the best for your interview. It is well known that hard work and the luck both are that major factor that plays important roles in every exam. 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Suddenly another person interrupted as he was looking at my cv, he told to the chairman that I got first Prize in solid modeling Contest. This was a curse for me for that interview. Chairman: So you got first prize in Modeling? Me: Yes sir. Chairman: What is Computer Aided Design? Me: I told. Chairman: You have been taught the Finite Element Methods course? Me: Yes sir. Chairman: Can you do the analysis of a cylindrical pressure vessel? Me: No sir, actually we just learnt the analysis of one dimensional objects. Chairman: But you know the basics of analysis steps? Me: Yes sir. Chairman: What will be the first step? Me: We will take the symmetry and will not require going through the analysis of whole section. Chairman: Draw the element of symmetry? Me: I drawn. Chairman: Next step? Me: Boundary conditions and Forces. Chairman: What will be the boundary conditions, forces etc.....? I could not give the answers, and the trials were wrong and I was totally confused. but he rammed me a lot and wasted almost 10 minutes. It was a bad impression that lead me through the darkness. Then he asked me to put the name of subjects I studied in B.Tech as our curriculum is different from other colleges curriculum, It has major emphasize on Design. So under pressure I was not able to recall the subjects. I started to recall them and listed on the paper but didn't minded to put them in the order I prepared. Actually I prepared Material science, Thermodynamics, Heat Transfer and Micro Metal Forming (for the fabrication of MEMS devices, a recent topic). So they just started asking the questions randomly from the subjects they got in that list. After a sometime chairman asked me about the subjects I am comfortable. I told and given the preference to Micro-Metal Forming that was a new topic for him and he decided to get out of the topic and asked about the issues when we go through the micro forming. I told that as we go from macro size to micro, the strength, isotropic behavior and surface roughness changes and affect a lot. Then he asked how surface roughness comes into picture? Me: As material thickness approaches towards micro size, the no. of grain boundaries becomes fewer and grain boundaries sizes are in the order of microns so the very early surface has a lot of deviations that comes in picture. Then he asked: What is inside the space between two grain boundaries; Gas or Vacuum? Me: Sir Vacuum. He Said: You are wrong, go and refer the books. and in this way he came out of the topic that he was trying for. So, I will suggest you not to give any new topic as the persons taking interview may or may not be comfortable with that and it may be a curse to you. In Thermo….. he asked He: there is a cylinder-piston system that contains a gas, a weight W is kept on piston what will be the pressure? Me: Sir W/(g*A)---A: area, g: gravity (It was wrong actually I was in such a pressure that to calculate the pressure I was using the formula M/A) Then another person asked me about "g", why I am using it ? I confidently said: sir to get the mass from weight He knew that I am confused so he asked me to derive it's dimension I derived then he asked me to derive the dimension of force by area and he asked me to compare, and I found my mistake. I said sorry and then He: I am giving it "Q" all the boundaries are insulated so that no heat goes outside, calculate it's final volume? Me: I was confused and was asking about a lot of irrelevant information needed to solve. He: This is all I told you now calculate the volume...no other information. I could not derive it. Then......Fluid: He: I am having an wedge shaped vessel (triangular shaped) I want to know the water level at different places, what will be the levels of water at different tubes? Me: Same level in every tube. He: why? Me: because of fluids property...pressure at a level is same at every point So the height raised will compensate for it. He: ok so, pressure is constant at all the points in same level but different at different levels? Me: Yes sir. He: So if I make two holes at different levels and fit a tube at outside from the vessel then water will flow? Me: yes sir. He: If I place a turbine in between the pipe then will the electricity produced? Me: No. He: why? Me: because water will flow once only. He: but pressure difference is continuously acting at two different levels? Me: as once water flows and the section gets filled pressure at the same level in vessel and pipe will be same, So no way it will flow again. This was a section where I was somewhat comfortable and answered correctly. SOM: Shear stresses, how shear stress comes ....Is bending stress and shear stress same and a lot....they make me totally confused. Mohr's Circle related questions. That I replied correctly. As you know that I am from Department of Mechanical Engineering. I qualified the written exam conducted by BARC and attended the interview. First let me tell you that this is the most genuine and toughest interview among all the PSUs. This is the best interview methodology that they adopt. They just ask for very basic questions of Intermediate (12th) level and want to check the basic understanding. Almost all the questions are practical questions no direct relation with the knowledge of core technical. In this way they look for the way you approach to solve a problem. Because the post they offer you is scientific officers’ post. This is a research oriented job that requires the great skills and knowledge to solve a real practical problem. So, this was a basic idea about the interview. Now let's talk about the methodology, actually they ask you 4-5 subjects in which you are more comfortable and ask the basic questions. But keep in mind that you are really comfortable with those subjects and you should be thoroughly prepared. Because they will try to divert you from your answer and will drill on topic till you surrender. But anyway you don't worry even if you are not able to solve a problem for whole but the way you approach and the basic concepts should be correct. They are generally the minimum time for interview is more than 45 minutes. Even the person they know will not be qualified; they drill him at least for 45 minutes. As the interview timing cross more than 45-60 minutes, your chance goes on increasing to get selected. Finally If they are satisfied with your performance then they give you a medical slip that insures your eligibility fir the interview. Final Result depends on the no. of posts and the merit list prepared on the basis of marks you achieved in written and interview. I wish you all the best for your interview. It is well known that hard work and the luck both are that major factor that plays important roles in every exam. Your Luck also plays an important role that by which panel you are going to be interviewed. During my interview I was a victim of bad luck so I could not qualified the interview. I had heard that the panel members being very helpful they bring you out of the pressure if you feel during the interview but this was not true in my case. Anyways, I entered in the room, there were 5 members. The committee chairman asked me about my hometown. The whole conversation was in Hindi, so the people who are from Hindi background they don't need to be afraid of this problem in PSU interviews. Then he asked me "Is it your first interview or you have gone through any other interview?", Me: "Sir this is my first interview". This normal conversation is just to make you feel good and to make you comfortable. Chairman: So you have done your B.Tech from IIIT? Me: Yes Sir. Suddenly another person interrupted as he was looking at my cv, he told to the chairman that I got first Prize in solid modeling Contest. This was a curse for me for that interview. Chairman: So you got first prize in Modeling? Me: Yes sir. Chairman: What is Computer Aided Design? Me: I told. Chairman: You have been taught the Finite Element Methods course? Me: Yes sir. Chairman: Can you do the analysis of a cylindrical pressure vessel? Me: No sir, actually we just learnt the analysis of one dimensional objects. Chairman: But you know the basics of analysis steps? Me: Yes sir. Chairman: What will be the first step? Me: We will take the symmetry and will not require going through the analysis of whole section. Chairman: Draw the element of symmetry? Me: I drawn. Chairman: Next step? Me: Boundary conditions and Forces. Chairman: What will be the boundary conditions, forces etc.....? I could not give the answers, and the trials were wrong and I was totally confused. but he rammed me a lot and wasted almost 10 minutes. It was a bad impression that lead me through the darkness. Then he asked me to put the name of subjects I studied in B.Tech as our curriculum is different from other colleges curriculum, It has major emphasize on Design. So under pressure I was not able to recall the subjects. I started to recall them and listed on the paper but didn't minded to put them in the order I prepared. Actually I prepared Material science, Thermodynamics, Heat Transfer and Micro Metal Forming (for the fabrication of MEMS devices, a recent topic). So they just started asking the questions randomly from the subjects they got in that list. After a sometime chairman asked me about the subjects I am comfortable. I told and given the preference to Micro-Metal Forming that was a new topic for him and he decided to get out of the topic and asked about the issues when we go through the micro forming. I told that as we go from macro size to micro, the strength, isotropic behavior and surface roughness changes and affect a lot. Then he asked how surface roughness comes into picture? Me: As material thickness approaches towards micro size, the no. of grain boundaries becomes fewer and grain boundaries sizes are in the order of microns so the very early surface has a lot of deviations that comes in picture. Then he asked: What is inside the space between two grain boundaries; Gas or Vacuum? Me: Sir Vacuum. He Said: You are wrong, go and refer the books. and in this way he came out of the topic that he was trying for. So, I will suggest you not to give any new topic as the persons taking interview may or may not be comfortable with that and it may be a curse to you. In Thermo….. he asked He: there is a cylinder-piston system that contains a gas, a weight W is kept on piston what will be the pressure? Me: Sir W/(g*A)---A: area, g: gravity (It was wrong actually I was in such a pressure that to calculate the pressure I was using the formula M/A) Then another person asked me about "g", why I am using it ? I confidently said: sir to get the mass from weight He knew that I am confused so he asked me to derive it's dimension I derived then he asked me to derive the dimension of force by area and he asked me to compare, and I found my mistake. I said sorry and then He: I am giving it "Q" all the boundaries are insulated so that no heat goes outside, calculate it's final volume? Me: I was confused and was asking about a lot of irrelevant information needed to solve. He: This is all I told you now calculate the volume...no other information. I could not derive it. Then......Fluid: He: I am having an wedge shaped vessel (triangular shaped) I want to know the water level at different places, what will be the levels of water at different tubes? Me: Same level in every tube. He: why? Me: because of fluids property...pressure at a level is same at every point So the height raised will compensate for it. He: ok so, pressure is constant at all the points in same level but different at different levels? Me: Yes sir. He: So if I make two holes at different levels and fit a tube at outside from the vessel then water will flow? Me: yes sir. He: If I place a turbine in between the pipe then will the electricity produced? Me: No. He: why? Me: because water will flow once only. He: but pressure difference is continuously acting at two different levels? Me: as once water flows and the section gets filled pressure at the same level in vessel and pipe will be same, So no way it will flow again. This was a section where I was somewhat comfortable and answered correctly. SOM: Shear stresses, how shear stress comes ....Is bending stress and shear stress same and a lot....they make me totally confused. Mohr's Circle related questions. That I replied correctly.

1474