Computer Science & Information Technology1

Q1. What are two senses in which the term random-access memory is used?

Q2.What is the difference between DRAM and SRAM in terms of application?

Q3. What is the difference between DRAM and SRAM in terms of characteristics such as speed, size, and  cost?

Q4.What are some applications for ROM?



Problems

P1. Consider a dynamic RAM that must be given a refresh cycle 64 times per ms. Each refresh operation requires 150 ns; a memory cycle requires 250 ns. What percentage of the memory’s total operating time must be given to refreshes?

P2. Consider a dynamic memory cell (DRAM) of RC circuit assume that C=50 ff (f = 10-15) & that leakage current through the transistor is about 9 pA (p=10-12). The voltage across the capacitor when it is fully charge is equal to 4.5 volt. The cell must be refreshed before this voltage drops below 3 volt. Estimate the minimum refresh rate.

P3. How many check bits are needed if the Hamming error correction code is used to detect single bit errors in a 1024-bit data word?

P4. A common unit of measure for failure rates of electronic components is the Failure
unIT (FIT), expressed as a rate of failures per billion device hours. Another well-known but less used measure is mean time between failures (MTBF), which is the average time of operation of a particular component until it fails. Consider a 1 MB memory of a 16-bit microprocessor with 256K 1 DRAMs. Calculate its MTBF assuming 2000 FITS for each DRAM.

P5. The memory of a particular microcomputer is built from 64K 1 DRAMs. According to the data sheet, the cell array of the DRAM is organized into 256 rows. Each row must be refreshed at least once every 4 ms. Suppose we refresh the memory on a strictly periodic basis.
a. What is the time period between successive refresh requests?
b. How long a refresh address counter do we need?

Solution-Click here

Material Science Problems

P1. A sheet of BCC iron 1 mm thick was exposed to a carburizing gas atmosphere on one side and a decarburizing atmosphere on the other side at 725°C. After having reached steady state, the iron was quickly cooled to room temperature. The carbon concentrations at the two surfaces of the sheet were determined to be 0.012 and 0.0075 wt%. Compute the diffusion coefficient if the diffusion flux is 1.4*10^-8 kg/m2-s. Hint: Use Equation to convert the concentrations from weight percent to kilograms of carbon per cubic meter of iron.

P2. The diffusion coefficients for silver in copper are given at two temperatures:

T (°C)    D (m2/s)
650        5.5 × 10–16
900        1.3 × 10–13

(a) Determine the values of D0 and Qd.
(b) What is the magnitude of D at 875°C?

P3. Aluminum atoms are to be diffused into a silicon wafer using both predeposition and drive-in heat treatments; the background concentration of Al in this silicon material is known to be 3x1019 atoms/m3. The drive-in diffusion treatment is to be carried out at 1050°C for a period of 4.0 h, which gives a junction depth xj of 3.0 micro meter. Compute the predeposition diffusion time at 950°C if the surface concentration is maintained at a constant level of 2x1025 atoms/m3. For the diffusion of Al in Si, values of Qd and D0 are 3.41 eV and 1.38x10^-4 m2/s, respectively.

P4. A cylindrical rod of copper (E = 110 GPa, 16x106 psi) having a yield strength of 240 MPa (35,000 psi) is to be subjected to a load of 6660 N (1500 lbf). If the length of the rod is 380 mm (15.0 in.), what must be the diameter to allow an elongation of 0.50 mm (0.020 in.)?

P5. Consider a cylindrical specimen of some hypothetical metal alloy that has a diameter of 8.0 mm (0.31 in.). A tensile force of 1000 N (225 lbf) produces an elastic reduction in diameter of 2.8x10^-4 mm (1.10x 10^-5 in.). Compute the modulus of elasticity for this alloy, given that Poisson's ratio is 0.30.

P6. A tensile test is performed on a metal specimen, and it is found that a true plastic strain of 0.2 is produced when a true stress of 575 Mpa; for the same metal the value of K is 860Mpa; calculate the true strain that results from the application of a true stress of 600Mpa

P7. A yield strength of a polycrystalline material increases from 120 MPa to 220 MPa on decreasing the grain diameter from 0.04 to 0.01 mm.  Find the yield strength for a grain size of ASTM 9.

P8. The yield strength of a polycrystalline material increases from 120 N/mm^2  on decreasing the average grain diameter from 0.04 mm to 0.01 mm. fine the yield strength for a grain size of 0.025 mm.

Solution-Click here

Joint CSIR-UGC Test For Junior Research Fellowship And Eligibility for Lectureship Syllabus

CSIR-NET/JRF ENGINEERING SCIENCES-Syllabus

EXAM SCHEME FOR ENGINEERING SCIENCES

TIME: 3 HOURS                                                         MAXIMUM MARKS: 200

Single Paper Test having Multiple Choice Questions (MCQs) is divided in three parts.

Part 'A'

This part shall carry 20 questions pertaining to General aptitude with emphasis on logical reasoning graphical analysis,analytical and numerical ability, quantitative comparisons, series formation, puzzles etc. The candidates shall be required to answer any 15 questions. Each question shall be of two marks. The total marks allocated to this section shall be 30 out of 200.

Part ‘B’ :

This part shall contain 25 questions related to Mathematics and Engineering Aptitude. Candidates shall be required to answer any 20 questions. Each question shall be of 3.5 marks. Total marks allocated to this section shall be 70 out of 200.

Part ‘C’ : 

Shall contain subject related question of the following 7 subject areas :

1. Computer Science & Information Technology
2 Electrical Science
3. Electronics
4. Materials Science
5. Fluid Mechanics
6. Solid Mechanics
7. Thermodynamics

Each subject area will carry 10 questions. Candidates shall be required to answer any 20 questions out of a total of 70 questions. Each question shall be of 5 marks. The total marks allocated to this part shall be 100 out of 200.There will be negative marking @25% for each wrong answer. To enable the candidates to go through the questions, the question paper booklet shall be distributed 15 minutes before the scheduled time of the exam. The answer sheet (OMR sheet) shall be distributed at the scheduled time of the exam.

CSIR-NET/JRF ENGINEERING SCIENCES-Syllabus

CSIR-NET/JRF-Syllabus and Scheme for Others

1. Chemical Sciences

                  TIME: 3 HOURS                                                         MAXIMUM MARKS: 200

CSIR-UGC (NET) Exam for Award of Junior Research Fellowship and Eligibility for Lecturership shall be a Single Paper Test having Multiple Choice Questions (MCQs). The question paper is divided in three parts

Part 'A' 

               This part shall carry 20 questions pertaining to General Science, Quantitative Reasoning & Analysis and Research Aptitude. The candidates shall be required to answer any 15 questions. Each question shall be of two marks. The total marks allocated to this section shall be 30 out of 200.

Part 'B'

                This part shall contain 50 Multiple Choice Questions(MCQs) generally covering the topics given in the syllabus. A candidate shall be required to answer any 35 questions. Each question shall be of two marks. The total marks allocated to this section shall be 70 out of 200.

Part 'C'

                This part shall contain 75 questions that are designed to test a candidate's knowledge of scientific concepts and/or application of the scientific concepts. The questions shall be of analytical nature where a candidate is expected to apply the scientific knowledge to arrive at the solution to the given scientific problem. A candidate shall be required to answer any 25 questions. Each question shall be of four marks. The total marks allocated to this section shall be 100 out of 200.

·             There will be negative marking @25% for each wrong answer.

·             To enable the candidates to go through the questions, the question paper booklet shall be distributed 15 minutes before the scheduled time of the exam. The Answer sheet shall be distributed at the scheduled time of the exam.

·             On completion of the exam i.e. at the scheduled closing time of the exam, the candidates shall be allowed to carry the Question Paper Booklet. No candidate is allowed to carry the Question Paper Booklet in case he/she chooses to leave the test before the scheduled closing time.

 For Syllabus Click here

2. Earth, Atmospheric, Ocean and Planetary Sciences

TIME: 3 HOURS                                                         MAXIMUM MARKS: 200

From June, 2011 CSIR-UGC (NET) Exam for Award of Junior Research Fellowship and Eligibility for Lecturership shall be a Single Paper Test having Multiple Choice Questions (MCQs). The question paper shall be divided in three parts.

Part 'A' 

                This part shall carry 20 questions pertaining to General Science, Quantitative Reasoning & Analysis and Research Aptitude. The candidates shall be required to answer any 15 questions. Each question shall be of two marks. The total marks allocated to this section shall be 30 out of 200.

Part 'B'

                This part shall contain 50 Multiple Choice Questions(MCQs) generally covering the topics given in the syllabus. A candidate shall be required to answer any 35 questions. Each question shall be of two marks. The total marks allocated to this section shall be 70 out of 200.

Part 'C'

                This part shall contain 80 questions that are designed to test a candidate's knowledge of scientific concepts and/or application of the scientific concepts. The questions shall be of analytical nature where a candidate is expected to apply the scientific knowledge to arrive at the solution to the given scientific problem. A candidate shall be required to answer any 25  questions. Each question shall be of 4 marks. The total marks allocated to this section shall be 100 out of 200.

·                      For Part ‘A’ and ‘B’ there will be Negative marking @25% for each wrong answer. The Negative marking for  Part ‘C’ shall be @ 33% for each wrong answer.

·                      To enable the candidates to go through the questions, the question paper booklet shall be distributed 15 minutes before the scheduled time of the exam. The Answer sheet shall be distributed at the scheduled time of the exam.

·                      On completion of the exam i.e. at the scheduled closing time of the exam, the candidates shall be allowed to carry the Question Paper Booklet. No candidate is allowed to carry the Question Paper Booklet in case he/she chooses to leave the test before the scheduled closing time.

For Syllabus Click here

3. Life Sciences

                                    TIME: 3 HOURS                                                         MAXIMUM MARKS: 200

CSIR-UGC (NET) Exam for Award of Junior Research Fellowship and Eligibility for Lecturership shall be a Single Paper Test having Multiple Choice Questions (MCQs). The question paper is divided in three parts

Part 'A' 

                This part shall carry 20 questions pertaining to General Science, Quantitative Reasoning & Analysis and Research Aptitude. The candidates shall be required to answer any 15 questions. Each question shall be of two marks. The total marks allocated to this section shall be 30 out of 200.

Part 'B'

                This part shall contain 50 Multiple Choice Questions(MCQs) generally covering the topics given in the syllabus. A candidate shall be required to answer any 35 questions. Each question shall be of two marks. The total marks allocated to this section shall be 70 out of 200.

Part 'C'

                This part shall contain 75 questions that are designed to test a candidate's knowledge of scientific concepts and/or application of the scientific concepts. The questions shall be of analytical nature where a candidate is expected to apply the scientific knowledge to arrive at the solution to the given scientific problem. A candidate shall be required to answer any 25 questions. Each question shall be of four marks. The total marks allocated to this section shall be 100 out of 200.

·                      There will be negative marking @25% for each wrong answer.

·                      To enable the candidates to go through the questions, the question paper booklet shall be distributed 15 minutes before the scheduled time of the exam. The Answer sheet shall be distributed at the scheduled time of the exam.

·                       On completion of the exam i.e. at the scheduled closing time of the exam, the candidates shall be allowed to carry the Question Paper Booklet. No candidate is allowed to carry the Question Paper Booklet in case he/she chooses to leave the test before the scheduled closing time.

For Syllabus Click here

4. Mathematical Sciences

TIME: 3 HOURS                                                         MAXIMUM MARKS: 200

CSIR-UGC (NET) Exam for Award of Junior Research Fellowship and Eligibility for Lecturership shall be a Single Paper Test having Multiple Choice Questions (MCQs). The question paper shall be divided in three parts.

Part 'A' 

                This part shall carry 20 questions pertaining to General Science, Quantitative Reasoning & Analysis and Research Aptitude. The candidates shall be required to answer any 15 questions. Each question shall be of two marks. The total marks allocated to this section shall be 30 out of 200.

Part 'B'

                This part shall contain 40 Multiple Choice Questions (MCQs) generally covering the topics given in the syllabus. A candidate shall be required to answer any 25 questions. Each question shall be of three marks. The total marks allocated to this section shall be 75 out of 200.

Part 'C'

                This part shall contain 60 questions that are designed to test a candidate's knowledge of scientific concepts and/or application of the scientific concepts. The questions shall be of analytical nature where a candidate is expected to apply the scientific knowledge to arrive at the solution to the given scientific problem. The questions in this part shall have multiple correct options. Credit in a question shall be given only on identification of ALL the correct options. No credit shall be allowed in a question if any incorrect option is marked as correct answer. No partial credit is allowed. A candidate shall be required to answer any 20 questions. Each question shall be of 4.75 marks. The total marks allocated to this section shall be 95 out of 200.

·                      For Part ‘A’ and ‘B’ there will be Negative marking @25% for each wrong answer. No Negative marking for Part ‘C’.

·                      To enable the candidates to go through the questions, the question paper booklet shall be distributed 15 minutes before the scheduled time of the exam. The Answer sheet shall be distributed at the scheduled time of the exam.

·                       On completion of the exam i.e. at the scheduled closing time of the exam, the candidates shall be allowed to carry the Question Paper Booklet. No candidate is allowed to carry the Question Paper Booklet in case he/she chooses to leave the test before the scheduled closing time.

             

 For Syllabus Click here

5. Physical Sciences

                         TIME: 3 HOURS                                                         MAXIMUM MARKS: 200

CSIR-UGC (NET) Exam for Award of Junior Research Fellowship and Eligibility for Lectureship shall be a Single Paper Test having Multiple Choice Questions (MCQs). The question paper shall be divided in three parts.

Part 'A' 

                This part shall carry 20 questions pertaining to General Science, Quantitative Reasoning & Analysis and Research Aptitude. The candidates shall be required to answer any 15 questions. Each question shall be of two marks. The total marks allocated to this section shall be 30 out of 200.

Part 'B'

                This part shall contain 25 Multiple Choice Questions (MCQs) generally covering the topics given in the Part ‘A’ (CORE) of syllabus. Each question shall be of 3.5 Marks. The total marks allocated to this section shall be 70 out of 200.Candidates are required to answer any 20 questions.

Part 'C'

                This part shall contain 30 questions from Part ‘B’ (Advanced) and Part ‘A’ that are designed to test a candidate's knowledge of scientific concepts and/or application of the scientific concepts. The questions shall be of analytical nature where a candidate is expected to apply the scientific knowledge to arrive at the solution to the given scientific problem. A candidate shall be required to answer any 20. Each question shall be of 5 Marks. The total marks allocated to this section shall be 100 out of 200.

v     There will be negative marking @25% for each wrong answer.

v     To enable the candidates to go through the questions, the question paper booklet shall be distributed 15 minutes before the scheduled time of the exam. The Answer sheet shall be distributed at the scheduled time of the exam.

v     On completion of the exam i.e. at the scheduled closing time of the exam, the candidates shall be allowed to carry the Question Paper Booklet. No candidate is allowed to carry the Question Paper Booklet in case he/she chooses to leave the test before the scheduled closing time.

For Syllabus Click here

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e competitive exam previous year question paper

CSIR NET JRF FOR ENGINEERING SCIENCE DECEMBER 2012 eQuestion-Click here
CSIR NET JRF FOR ENGINEERING SCIENCE DECEMBER 2012 eKey-Click here
CSIR NET JRF FOR ENGINEERING SCIENCE JUNE 2013 eQuestion-Click here
CSIR NET JRF FOR ENGINEERING SCIENCE JUNE 2013 eKey-Click here

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