200+ Quality Controller Interview Questions and Answers

Chemistry is the study of matter and its properties. Organic chemistry deals with carbon-based compounds while inorganic chemistry deals with non-carbon-based compounds.

• Chemistry is a branch of science that deals with the composition, structure, properties, and reactions of matter.

• Organic chemistry is the study of carbon-based compounds, including hydrocarbons, carbohydrates, proteins, and nucleic acids.

• Inorganic chemistry is the study of non-carbon-based compounds, including...read more

HPLC stands for High Performance Liquid Chromatography. It is a technique used to separate, identify, and quantify components in a mixture.

• HPLC is based on the principle of separating components in a mixture using a liquid mobile phase that carries the sample through a stationary phase.

• TLC stands for Thin Layer Chromatography, which is a technique for separating and analyzing mixtures based on their differential migration on a thin layer of adsorbent material.

• Chromatography i...read more

Nucleic acids are biomolecules essential for storing and transmitting genetic information in cells.

• Nucleic acids are made up of nucleotides, which consist of a sugar, a phosphate group, and a nitrogenous base.

• There are two types of nucleic acids: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).

• DNA carries genetic information and is responsible for inheritance, while RNA plays a role in protein synthesis.

• Nucleic acids are crucial for the replication and expression of ge...read more

PCR is a technique used to amplify a specific DNA sequence, producing millions of copies for analysis.

• PCR involves cycles of heating and cooling to denature, anneal, and extend DNA strands.

• Types of PCR include conventional PCR, quantitative PCR (qPCR), reverse transcription PCR (RT-PCR), and digital PCR.

• Conventional PCR is used for DNA amplification, qPCR for quantifying DNA, RT-PCR for RNA amplification, and digital PCR for absolute quantification.

Real-Time PCR allows for monitoring the amplification of DNA in real-time, while conventional PCR requires post-amplification analysis.

• Real-Time PCR provides quantitative data in real-time, while conventional PCR only provides qualitative data after the reaction is complete.

• Real-Time PCR uses fluorescent dyes or probes to monitor amplification as it occurs, while conventional PCR relies on gel electrophoresis to visualize the final products.

• Real-Time PCR is more sensitive and...read more

DNA extraction and isolation is the process of obtaining DNA from cells for further analysis.

• Cells are lysed to release DNA

• Proteins and other contaminants are removed through precipitation or column purification

• DNA is then precipitated and washed to remove impurities

• Finally, DNA is resuspended in a buffer for storage or analysis

Shuttering can be managed without removing supports under slab and pourstrip by using adjustable props and beams.

• Use adjustable props to support the slab and pourstrip while removing the shuttering.

• Install beams to transfer the load from the slab to the props, allowing the supports to be removed.

• Ensure proper alignment and spacing of props and beams to distribute the load evenly.

• Regularly check and adjust the props and beams to maintain stability during the construction proce...read more

I will identify the root cause of the problem, implement corrective actions, and monitor the effectiveness of the solutions.

• Investigate the issue to determine the root cause

• Implement corrective actions to address the problem

• Monitor the effectiveness of the solutions to ensure the problem is resolved

• Document the entire process for future reference

Checks in concrete include slump test, air content test, temperature monitoring. At column and slab junction, check for proper reinforcement placement, formwork alignment, and concrete pouring.

• Perform slump test to ensure proper consistency of concrete

• Check air content to ensure proper durability and workability

• Monitor temperature to prevent issues like thermal cracking

• At column and slab junction, check reinforcement placement for proper strength

• Ensure formwork alignment to p...read more

Quality checking involves inspecting products or services to ensure they meet certain standards.

• Quality checking involves examining products or services to ensure they meet certain standards

• This can involve visual inspection, testing, or other methods depending on the product or service

• Experience in quality checking can vary, but typically requires knowledge of industry standards and regulations

• To check the quality status, one must compare the product or service to establishe...read more

Minimum compressive strength of OPC 43 grade cement is 43 MPa.

• OPC 43 grade cement has a minimum compressive strength of 43 MPa

• The compressive strength of cement is a measure of its ability to withstand compressive loads

• OPC stands for Ordinary Portland Cement

• The grade of cement indicates its strength and quality

There are 118 elements in the periodic table.

• There are 118 known elements in the periodic table.

• Elements are organized by atomic number, electron configuration, and recurring chemical properties.

• Examples of elements include hydrogen, oxygen, gold, and uranium.

The role of a quality controller during production is to ensure that products meet the required standards and specifications.

• Monitoring and inspecting production processes

• Identifying defects and deviations from standards

• Implementing corrective actions to prevent defects

• Maintaining records and documentation of quality control activities

• Collaborating with production teams to improve processes

• Ensuring compliance with regulatory requirements

• Conducting audits and quality assessmen...read more

Harmful bacteria and their limits vary depending on the context and industry.

• Common harmful bacteria include Salmonella, E. coli, and Listeria.

• Limits for harmful bacteria in food are regulated by government agencies.

• In the medical field, harmful bacteria can cause infections and diseases.

• Different industries have specific guidelines for acceptable levels of bacteria.

• Regular testing and quality control measures are essential to ensure safety.

Quality checking involves inspecting products or services to ensure they meet standards. Experience and attention to detail are key.

• Quality checking involves inspecting products or services to ensure they meet standards

• This can include visual inspections, measurements, and testing

• Experience and attention to detail are key in identifying potential issues and ensuring quality

• Quality checking can involve using tools such as checklists, statistical process control, and quality co...read more

HPLC stands for High Performance Liquid Chromatography. It is a technique used to separate, identify, and quantify components in a mixture.

• HPLC is based on the principle of separating components in a mixture using a liquid mobile phase and a solid stationary phase.

• TLC (Thin Layer Chromatography) is another chromatographic technique where the stationary phase is a thin layer of adsorbent material on a flat support.

• Chromatography is a technique used to separate and analyze mixt...read more

The presence of chlorine can be confirmed by adding nitric acid and silver nitrate to a sample, resulting in a curdy white precipitate.

• Mix 1 ml sample with 5 ml nitric acid and 5 ml silver nitrate

• Add 10 ml water and observe for curdy white precipitate

• Presence of chlorine confirmed if precipitate forms

I have extensive technical knowledge of pharmaceutical production.

• I am familiar with Good Manufacturing Practices (GMP) and Quality Control (QC) procedures.

• I have experience in operating and maintaining production equipment such as tablet presses, capsule fillers, and packaging machines.

• I am knowledgeable in the formulation and compounding of pharmaceutical products.

• I am familiar with the various stages of pharmaceutical production, including raw material testing, in-process ...read more

Different types of measuring tools include rulers, calipers, micrometers, tape measures, and gauges.

• Ruler - used for measuring straight lines and lengths

• Calipers - used for measuring the distance between two opposite sides of an object

• Micrometers - used for measuring very small distances or thicknesses

• Tape measure - used for measuring longer distances or circumferences

• Gauges - used for measuring specific dimensions or parameters

Quality assurance for a product should start at the beginning of the product development process.

• Start quality assurance during the design phase to prevent issues from arising later on

• Implement quality control measures during manufacturing to ensure consistency and reliability

• Conduct regular inspections and testing throughout the production process

• Involve stakeholders in the quality assurance process to gather feedback and make improvements

• Continuously monitor and evaluate th...read more

The Listcount of vernier caliper & micrometers is 2.

• The Listcount of vernier caliper is 1.

• The Listcount of micrometers is 1.

UV spectroscopy is a technique used to analyze the absorption and transmission of ultraviolet light by a sample.

• UV spectroscopy involves measuring the absorbance of ultraviolet light by a sample.

• It works based on the principle that molecules absorb UV light at specific wavelengths.

• The amount of absorption is proportional to the concentration of the absorbing species in the sample.

• UV spectroscopy is commonly used in pharmaceutical, environmental, and biochemical analysis.

The pourstrip is a critical component for support in quality control. Its removal could lead to potential issues in product packaging and quality assurance.

• Loss of structural integrity in packaging

• Increased risk of contamination or tampering

• Difficulty in handling and storage of products

• Potential impact on product shelf life and quality

• Need for alternative support measures or redesign of packaging

I have knowledge in quality assurance processes, tools, methodologies, and standards to ensure products meet quality standards.

• Understanding of quality control processes and procedures

• Knowledge of quality assurance tools and software

• Familiarity with quality assurance methodologies such as Six Sigma or Lean

• Experience in conducting quality audits and inspections

• Ability to analyze data and identify areas for improvement

• Strong attention to detail and problem-solving skills

Climatic fruits and vegetables are those that require specific climate conditions to grow, while non-climatic ones can grow in various climates.

• Climatic fruits and vegetables need specific temperature, humidity, and sunlight conditions to thrive

• Non-climatic fruits and vegetables can grow in a wider range of climates

• Examples of climatic fruits: bananas, pineapples, mangoes

• Examples of non-climatic fruits: apples, oranges, strawberries

• Examples of climatic vegetables: tomatoes, c...read more

UV spectroscopy is a technique that uses ultraviolet light to measure the absorbance of a sample.

• UV spectroscopy measures the absorbance of a sample in the ultraviolet region of the electromagnetic spectrum.

• It is based on the principle that molecules absorb light at specific wavelengths.

• UV spectroscopy is commonly used in the analysis of organic compounds, such as proteins and nucleic acids.

• It can be used to determine the concentration of a sample, as well as to identify unkn...read more

Food should be stored at a temperature below 40°F (4°C) or above 140°F (60°C).

• Cold food should be stored at or below 40°F (4°C) to prevent bacterial growth.

• Hot food should be stored at or above 140°F (60°C) to prevent bacterial growth.

• Refrigerators should be set to a temperature between 34°F (1°C) and 40°F (4°C).

• Freezers should be set to a temperature of 0°F (-18°C) or below.

Standard quality control procedures involve several stages to ensure the quality of products or services.

• 1. Planning and designing the quality control process

• 2. Sampling and testing the products or services

• 3. Analyzing the results and identifying any deviations from standards

• 4. Implementing corrective actions if necessary

• 5. Monitoring and documenting the entire quality control process

To culture bacteria, aseptic techniques are used to transfer a small sample of bacteria onto a sterile growth medium and then incubated at the appropriate temperature.

• Prepare the agar plates or broth media according to the specific requirements of the bacteria being cultured.

• Use aseptic techniques to transfer a small sample of bacteria onto the agar plate or into the broth media.

• Incubate the plates or broth at the appropriate temperature for the specific bacteria being cultur...read more

Maintaining hygiene condition of product is crucial for quality control.

• Ensure proper cleaning and sanitation of equipment and facilities.

• Implement strict quality control measures to prevent contamination.

• Train employees on proper hygiene practices and provide necessary equipment.

• Regularly monitor and test products for any signs of contamination.

• Follow industry regulations and guidelines for hygiene and sanitation.

• Use appropriate packaging and storage methods to prevent conta...read more

Chlorine can be identified by its distinct smell. Nitric acid molecular formula is HNO3. Acetic acid molecular formula is CH3COOH.

• Chlorine can be identified by its pungent smell similar to bleach.

• Nitric acid molecular formula is HNO3.

• Acetic acid molecular formula is CH3COOH.

Purines and pyrimidines are types of nitrogenous bases found in DNA and RNA molecules.

• Purines are double-ring structures (adenine, guanine)

• Pyrimidines are single-ring structures (cytosine, thymine, uracil)

• They are essential components of nucleic acids and play a crucial role in genetic information transfer

Quality control is the process of ensuring that products or services meet the desired level of quality.

• It involves inspecting and testing products or services to identify defects or issues.

• It helps to prevent defects and improve overall quality.

• It can be used in various industries such as manufacturing, healthcare, and software development.

• Examples include checking the accuracy of medical test results, testing the durability of a product, and reviewing code for errors.

• Quality...read more

The process for conducting tests in a laboratory involves sample collection, preparation, analysis, and interpretation of results.

• Collect samples from the source

• Prepare samples for testing (e.g. extraction, dilution)

• Conduct tests using appropriate equipment and methods

• Analyze test results for accuracy and consistency

• Interpret results based on established criteria

• Document findings and report results

Noble gases are a group of chemical elements with very low reactivity and full outer electron shells.

• Noble gases are located in Group 18 of the periodic table.

• They are also known as inert gases because they rarely react with other elements.

• Examples of noble gases include helium, neon, argon, krypton, xenon, and radon.

Temperature is important in food storage to prevent bacterial growth and spoilage.

• High temperatures can cause bacteria to multiply rapidly, leading to foodborne illnesses

• Low temperatures can slow down or stop bacterial growth, preserving the quality and safety of food

• Different types of food require different storage temperatures, such as refrigeration for dairy products and freezing for meat

• Monitoring and controlling temperature is crucial in preventing food spoilage and ensu...read more

To maintain production quality, it is important to implement quality control measures, train employees, use standardized processes, and continuously monitor and improve the production process.

• Implement quality control measures such as regular inspections, testing, and audits

• Train employees on quality standards, procedures, and best practices

• Use standardized processes and documentation to ensure consistency

• Continuously monitor and measure key quality indicators

• Implement correc...read more

A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction.

• Transformers are used to increase or decrease the voltage of an alternating current (AC) power supply.

• There are two main types of transformers: step-up transformers and step-down transformers.

• The primary winding of a transformer is connected to the input voltage source, while the secondary winding is connected to the output load.

• Transformers ar...read more

Calibration of UV spectroscopy involves verifying the accuracy of the instrument by comparing it to a known standard.

• Calibration ensures that the instrument is providing accurate and reliable measurements.

• A known standard, such as a certified reference material, is used to verify the accuracy of the instrument.

• Calibration should be performed regularly to ensure consistent and reliable results.

• Factors such as temperature, humidity, and wavelength range can affect the accuracy ...read more

The question covers types of titrations, Beer-Lambert's law, and the range of UV and its principle.

• Types of titrations include acid-base, redox, complexometric, and precipitation titrations.

• Beer-Lambert's law relates the absorbance of light to the concentration of a solution.

• The range of UV is typically between 200-400 nm, and it is used for spectroscopy and chromatography.

• The principle of UV is based on the absorption of light by molecules, which can be used to identify and ...read more

Solution, solvent, and solute are terms used in chemistry to describe the components of a homogeneous mixture.

• A solution is a homogeneous mixture composed of a solvent and one or more solutes.

• The solvent is the substance that dissolves the solute(s) to form the solution.

• The solute is the substance that is dissolved in the solvent to form the solution.

• For example, in a saltwater solution, water is the solvent and salt is the solute.

I would use alternative methods such as pH strips or a pH meter to test acidity or alkalinity.

• Use pH strips to test acidity or alkalinity

• Use a pH meter for more accurate results

• Consider ordering more litmus paper for future use

Shear force is the force that acts perpendicular to the axis of the beam, while bending moment is the force that causes a beam to bend.

• Shear force is the force that acts perpendicular to the axis of the beam.

• Bending moment is the force that causes a beam to bend.

• Shear force and bending moment are important concepts in structural engineering.

• Shear force and bending moment diagrams are used to analyze the stresses in a beam.

• Shear force and bending moment are related to each oth...read more

Contamination on a medical device is checked through visual inspection, microbial testing, and chemical analysis.

• Perform visual inspection for any visible signs of contamination such as discoloration, debris, or foreign particles

• Conduct microbial testing to check for the presence of harmful microorganisms that can cause infections

• Use chemical analysis to detect any residues or contaminants that may be present on the device

• Follow established protocols and guidelines for contam...read more

Solvent technical specifications include boiling point, flash point, density, and solubility.

• Boiling point: The temperature at which the solvent changes from liquid to gas.

• Flash point: The lowest temperature at which the solvent can vaporize to form an ignitable mixture in air.

• Density: The mass per unit volume of the solvent.

• Solubility: The ability of the solvent to dissolve other substances.

• Example: Acetone has a boiling point of 56.05°C, flash point of -20°C, density of 0.7...read more

Breather in a transformer helps to prevent moisture and dust from entering the transformer tank.

• Breather allows air to enter and exit the transformer tank as the oil expands and contracts during operation.

• It contains silica gel or other desiccants to absorb moisture from the air entering the transformer.

• Prevents the formation of sludge and acids inside the transformer due to moisture contamination.

• Regular maintenance and replacement of the breather is necessary to ensure prop...read more

The 6 tools of quality control are essential techniques used in quality management to ensure products meet standards and customer expectations.

• Check sheets: Used to collect and analyze data in a systematic way.

• Control charts: Graphical tools to monitor processes over time.

• Histograms: Visual representation of data distribution.

• Pareto charts: Helps identify the most significant factors affecting quality.

• Scatter diagrams: Shows the relationship between two variables.

• Cause-and-ef...read more