Punjab University offers old question papers for ME-Chemical, ME-Food Technology (FT), and ME-Electrical Engineering and ME-Bio subjects.
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These pu previous year question papers for ME-CHEMICAL, ME-FT, ME-ELECTRIC, BBIIO can help students understand the exam format and key topics. Reviewing these pu previous papers can improve preparation, providing insight into the types of questions asked and aiding in better exam performance.
PU Old Question Paper for ME-CHEMICAL (Master of Engineering in Chemical Engineering)
Subject: Process Dynamics and Control
Question: Define a transfer function and give an example.
Answer: A transfer function is a mathematical representation of the relationship between the input and output of a linear, time-invariant system. Example: G(s)=1s+1G(s) = \frac{1}{s+1}G(s)=s+11.
Question: What is the purpose of a PID controller?
Answer: A PID controller is used to maintain the desired output of a system by adjusting the process control inputs.
Question: Explain the concept of feedback control.
Answer: Feedback control involves using measurements of the output to adjust the input to maintain the desired performance.
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Question: What is the difference between open-loop and closed-loop control systems?
Answer: Open-loop systems do not use feedback to adjust their actions, while closed-loop systems use feedback to ensure the output meets the desired setpoint.
Question: Define process gain and time constant in a first-order system.
Answer: Process gain is the ratio of the change in output to the change in input, and the time constant is the time required for the process to reach 63.2% of its final value after a step change in input.
Question: What is the significance of the Nyquist plot?
Answer: The Nyquist plot is used to assess the stability of a control system by plotting the frequency response of the system.
Question: Describe the Ziegler-Nichols tuning method.
Answer: The Ziegler-Nichols method provides empirical rules for setting the parameters of PID controllers based on the system’s response to a step input or its ultimate gain and period.
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Question: What are the typical components of a control system?
Answer: Typical components include sensors, controllers, actuators, and the process being controlled.
Question: How does a lead compensator improve system performance?
Answer: A lead compensator improves system performance by increasing the phase margin, which enhances stability and transient response.
Question: Explain the concept of process dead time.
Answer: Process dead time is the delay between when an input is applied to a process and when the effect of that input is observed in the output.
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PU Old Question Paper for ME-FT (Master of Engineering in Food Technology)
Subject: Food Process Engineering
Question: What is the principle of thermal processing in food preservation?
Answer: Thermal processing involves using heat to destroy pathogenic microorganisms and enzymes to extend shelf life.
Question: Explain the process of pasteurization.
Answer: Pasteurization is a mild heat treatment that kills harmful bacteria in food and beverages without significantly affecting the taste or nutritional value.
Question: What is the role of drying in food preservation?
Answer: Drying removes moisture from food, inhibiting the growth of microorganisms and enzymatic reactions that cause spoilage.
Question: Describe the concept of aseptic processing.
Answer: Aseptic processing involves sterilizing the food and packaging separately before combining them in a sterile environment.
Question: What is the significance of the water activity (aw) in food preservation?
Answer: Water activity measures the availability of water for microbial growth, with lower values indicating reduced spoilage potential.
Question: Explain the principle of freeze-drying.
Answer: Freeze-drying removes water from food by sublimation, preserving the structure and nutrients while extending shelf life.
Question: What are the main factors affecting the shelf life of food products?
Answer: Main factors include temperature, humidity, light, oxygen, and microbial contamination.
Question: Define the term “hurdle technology” in food preservation.
Answer: Hurdle technology combines multiple preservation methods to improve safety and extend shelf life by creating multiple barriers to microbial growth.
Question: What is the importance of pH in food preservation?
Answer: pH affects the growth of microorganisms, with acidic conditions inhibiting the growth of many pathogens and spoilage organisms.
Question: Describe the process of canning.
Answer: Canning involves sealing food in containers and heating them to destroy microorganisms and enzymes, creating a vacuum seal that prevents recontamination.
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PU Old Question Paper for ME-ELECTRIC (Master of Engineering in Electrical Engineering)
Subject: Power Systems
Question: What are the main components of an electrical power system?
Answer: The main components include generation, transmission, distribution, and consumption systems.
Question: Explain the concept of load flow analysis.
Answer: Load flow analysis determines the voltage, current, and power flows in a power system under steady-state conditions.
Question: What is the significance of the per-unit system in power engineering?
Answer: The per-unit system simplifies calculations by normalizing system quantities, making it easier to compare and analyze different parts of the system.
Question: Describe the operation of a synchronous generator.
Answer: A synchronous generator converts mechanical energy into electrical energy using electromagnetic induction, maintaining a constant speed to match the grid frequency.
Question: What is the role of a transformer in a power system?
Answer: Transformers change the voltage levels in a power system, enabling efficient transmission and distribution of electricity.
Question: Explain the concept of reactive power and its importance in power systems.
Answer: Reactive power is the component of alternating current electricity that does not transfer energy but is necessary for maintaining voltage levels and the stability of the power system.
Question: What are the causes and effects of harmonics in power systems?
Answer: Harmonics are caused by non-linear loads and can result in power quality issues, overheating of equipment, and increased losses.
Question: Describe the principle of operation of a circuit breaker.
Answer: A circuit breaker automatically interrupts the flow of current in a circuit when it detects an overload or short circuit, protecting the system from damage.
Question: What is the significance of the power factor in electrical systems?
Answer: The power factor indicates the efficiency of power usage, with a higher power factor signifying more efficient utilization of electrical power.
Question: Explain the concept of grid stability and the factors that affect it.
Answer: Grid stability refers to the ability of a power system to maintain continuous operation despite disturbances. Factors affecting it include generation and load balance, frequency control, and system inertia.
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M.E-BIO (Master of Engineering in Biotechnology)
Subject: Bioprocess Engineering
Question: What is the principle of microbial fermentation?
Answer: Microbial fermentation is the metabolic process by which microorganisms convert organic substrates into products such as ethanol, lactic acid, and biofuels.
Question: Describe the steps involved in downstream processing.
Answer: Downstream processing includes separation, purification, and concentration of the desired product from the fermentation broth, followed by formulation and packaging.
Question: Explain the concept of a chemostat in continuous culture.
Answer: A chemostat is a bioreactor where the culture is continuously fed with nutrients and the product is simultaneously removed, maintaining a steady state of microbial growth.
Question: What are monoclonal antibodies and their applications?
Answer: Monoclonal antibodies are identical antibodies produced by a single clone of cells, used in diagnostics, therapeutics, and research.
Question: Describe the principle of recombinant DNA technology.
Answer: Recombinant DNA technology involves combining DNA from different organisms to produce new genetic combinations, enabling the production of proteins, vaccines, and genetically modified organisms.
Question: What is the role of bioreactors in bioprocessing?
Answer: Bioreactors provide a controlled environment for the growth of microorganisms or cells to produce biological products on a large scale.
Question: Explain the concept of metabolic engineering.
Answer: Metabolic engineering involves modifying the metabolic pathways of an organism to enhance the production of a specific substance or create new products.
Question: What are the advantages of using immobilized enzymes?
Answer: Immobilized enzymes offer benefits such as reusability, stability, and ease of separation from reaction products.
Question: Describe the process of cell culture in biotechnology.
Answer: Cell culture involves growing cells under controlled conditions, typically outside their natural environment, for research, drug development, and production of biologics.
Question: What is the significance of scale-up in bioprocessing?
Answer: Scale-up is the process of increasing the production capacity from laboratory to industrial scale, ensuring that the process remains efficient and cost-effective.
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Punjab University Exam Pattern for ME-Chemical, ME-Food Technology (FT), and ME-Electrical (Old Scheme)
ME-Chemical Engineering
Exam Structure:
Duration: 2 years (divided into 4 semesters)
Subjects Covered: Advanced topics in Chemical Engineering such as Thermodynamics, Process Design, Chemical Reaction Engineering, and Transport Phenomena.
Assessment: Combination of internal assessments (assignments, projects, presentations) and end-semester examinations.
End-Semester Exam Pattern:
Type of Questions:
Objective Type (Multiple Choice Questions)
Subjective Type (Short Answer Questions, Long Answer Questions, Numerical Problems)
Total Marks: Each paper is generally 100 marks.
Duration: 3 hours per paper.
Passing Criteria: Minimum 50% in each paper and aggregate 50% in all subjects combined.
ME-Food Technology (FT)
Exam Structure:
Duration: 2 years (divided into 4 semesters)
Subjects Covered: Advanced topics in Food Technology such as Food Chemistry, Food Processing, Food Safety, and Quality Control.
Assessment: Combination of internal assessments (seminars, assignments, practicals) and end-semester examinations.
End-Semester Exam Pattern:
Type of Questions:
Objective Type (Multiple Choice Questions)
Subjective Type (Short Answer Questions, Long Answer Questions, Case Studies)
Total Marks: Each paper is generally 100 marks.
Duration: 3 hours per paper.
Passing Criteria: Minimum 50% in each paper and aggregate 50% in all subjects combined.
ME-Electrical Engineering
Exam Structure:
Duration: 2 years (divided into 4 semesters)
Subjects Covered: Advanced topics in Electrical Engineering such as Power Systems, Control Systems, Electrical Machines, and Digital Electronics.
Assessment: Combination of internal assessments (lab work, projects, presentations) and end-semester examinations.
End-Semester Exam Pattern:
Type of Questions:
Objective Type (Multiple Choice Questions)
Subjective Type (Short Answer Questions, Long Answer Questions, Problem Solving)
Total Marks: Each paper is generally 100 marks.
Duration: 3 hours per paper.
Passing Criteria: Minimum 50% in each paper and aggregate 50% in all subjects combined.
General Guidelines:
Attendance: A minimum of 75% attendance is required to be eligible for the examinations.
Internal Assessments: Regular participation and submission of assignments are crucial as they contribute significantly to the final grades.
Re-evaluation: Students can apply for re-evaluation of their answer scripts if dissatisfied with the results, subject to university rules and deadlines.
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