Calibration – principles, definitions and general procedures MCQs With Answer

Calibration – principles, definitions and general procedures MCQs With Answer

Calibration is a foundational concept in pharmaceutical analysis, ensuring instruments measure accurately and reliably. This introduction covers core *principles*, key *definitions* (accuracy, precision, traceability, uncertainty), and general *calibration procedures* for balances, pipettes, spectrophotometers and HPLC detectors. B. Pharm students should grasp calibration planning, use of reference standards, documentation, frequency, acceptance criteria, and the difference between verification, adjustment and validation. Understanding environmental effects, SOPs, calibration certificates, and regulatory expectations (ISO/IEC 17025, GLP) strengthens practical competence. Clear knowledge of calibration reduces analytical error, ensures patient safety, and supports quality systems. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the primary purpose of calibration in pharmaceutical instrumentation?

• To make an instrument faster
• To ensure measurement accuracy and traceability to standards
• To replace the instrument periodically
• To increase instrument sensitivity only

Correct Answer: To ensure measurement accuracy and traceability to standards

Q2. Which term describes the closeness of agreement between a measured value and the true value?

• Precision
• Robustness
• Accuracy
• Selectivity

Correct Answer: Accuracy

Q3. Which concept refers to the spread of repeated measurements under the same conditions?

• Bias
• Precision
• Traceability
• Calibration

Correct Answer: Precision

Q4. What does traceability in calibration mean?

• Direct comparison to an international or national standard through an unbroken chain of calibrations
• Keeping records indefinitely
• Only using internal laboratory standards
• Replacing consumables frequently

Correct Answer: Direct comparison to an international or national standard through an unbroken chain of calibrations

Q5. Which document provides formal evidence of a calibration and its results?

• Calibration certificate
• Purchase order
• Equipment manual
• Training log

Correct Answer: Calibration certificate

Q6. Which calibration activity involves checking instrument performance without making adjustments?

• Adjustment
• Verification
• Qualification
• Validation

Correct Answer: Verification

Q7. What is an important environmental factor to control during balance calibration?

• Ambient light spectrum
• Temperature and vibration
• Magnetic field only
• Software version

Correct Answer: Temperature and vibration

Q8. Which standard is commonly referenced for laboratory calibration and testing competence?

• ISO 9001
• ISO/IEC 17025
• ICH Q7
• GMP Annex 11

Correct Answer: ISO/IEC 17025

Q9. In a calibration certificate, what does uncertainty express?

• The guaranteed true value
• The range within which the true value is estimated to lie with a stated probability
• The instrument serial number
• The maintenance schedule

Correct Answer: The range within which the true value is estimated to lie with a stated probability

Q10. Which of the following is a primary reference standard used for weight calibration?

• Volumetric flask
• Certified calibration weight
• pH buffer
• Spectral lamp

Correct Answer: Certified calibration weight

Q11. What is the difference between calibration and validation?

• Calibration checks and adjusts instruments; validation confirms a method performs as intended
• Calibration is only for software; validation is only for hardware
• Calibration is optional while validation is mandatory
• There is no difference

Correct Answer: Calibration checks and adjusts instruments; validation confirms a method performs as intended

Q12. Which calibration approach establishes a relationship between instrument response and known concentrations?

• Calibration curve or standard curve
• Verification check
• Preventive maintenance
• Instrument qualification

Correct Answer: Calibration curve or standard curve

Q13. For a pipette, which check is typically performed daily by lab staff?

• Full adjustment service
• Gravimetric performance check
• Replacement of seals
• Calibration certificate renewal

Correct Answer: Gravimetric performance check

Q14. What does “linearity” describe in calibration of analytical instruments?

• Instrument drift over time
• The proportional response over a specified measurement range
• The ability to detect the lowest concentration only
• The instrument warranty period

Correct Answer: The proportional response over a specified measurement range

Q15. Which action is appropriate if an instrument fails calibration acceptance criteria?

• Continue using it without record
• Adjust or repair, then re-calibrate and document findings
• Discard all previous data without investigation
• Increase sample size to compensate

Correct Answer: Adjust or repair, then re-calibrate and document findings

Q16. Which item is essential in a calibration SOP?

• Operator’s favorite procedures
• Detailed stepwise procedure, acceptance criteria, and documentation requirements
• Only equipment serial numbers
• Company marketing plan

Correct Answer: Detailed stepwise procedure, acceptance criteria, and documentation requirements

Q17. Which term indicates a systematic difference between measured and true values?

• Random error
• Bias
• Precision
• Resolution

Correct Answer: Bias

Q18. What is a common acceptable balance calibration tolerance for an analytical microbalance?

• Several grams
• Microgram-level uncertainty specified by manufacturer or lab SOP
• No tolerance required
• Only visual checks are sufficient

Correct Answer: Microgram-level uncertainty specified by manufacturer or lab SOP

Q19. Who is typically responsible for approving calibration certificates in a pharmaceutical laboratory?

• Laboratory technician only
• Qualified calibration personnel or QA representative
• External courier
• Any intern

Correct Answer: Qualified calibration personnel or QA representative

Q20. Which calibration frequency factor should be considered when scheduling calibrations?

• Manufacturer recommendation, usage, criticality and regulatory requirements
• Only the purchase date
• Employee preference
• Random selection

Correct Answer: Manufacturer recommendation, usage, criticality and regulatory requirements

Q21. What is the role of a reference material in calibration?

• Decorative use in lab
• Provides known properties to verify instrument accuracy
• Acts as a replacement for SOPs
• Only used for training

Correct Answer: Provides known properties to verify instrument accuracy

Q22. Which is an example of an external calibration service benefit?

• Reduces documentation needs
• Provides traceable calibration to national standards and expert service
• Makes instruments immune to failure
• Eliminates the need for internal checks

Correct Answer: Provides traceable calibration to national standards and expert service

Q23. How is measurement uncertainty commonly expressed in calibration results?

• As a single unqualified number
• As an interval around the measured value with a confidence level
• Only as a percentage of instrument age
• As a list of possible causes

Correct Answer: As an interval around the measured value with a confidence level

Q24. What is the best practice for documenting calibration adjustments?

• No documentation needed if adjustment is small
• Record reason, procedures, pre- and post-adjustment results, and approval
• Only record the date
• Document only after external audit

Correct Answer: Record reason, procedures, pre- and post-adjustment results, and approval

Q25. Which calibration check is appropriate for a UV-Vis spectrophotometer?

• Blank reading only
• Wavelength accuracy using certified standards and photometric accuracy checks
• Replacing lamps weekly without testing
• Only checking the power cord

Correct Answer: Wavelength accuracy using certified standards and photometric accuracy checks

Q26. What does “as-found/as-left” report indicate in calibration?

• Environmental conditions during shipment
• Instrument condition before adjustment (as-found) and after adjustment (as-left)
• Only the technician’s signature
• Inventory list of spare parts

Correct Answer: Instrument condition before adjustment (as-found) and after adjustment (as-left)

Q27. Which error type is random and can be reduced by increasing the number of measurements?

• Systematic error
• Random error
• Calibration certificate error
• Documentation error

Correct Answer: Random error

Q28. What should be done when transferring an instrument between labs regarding calibration?

• Use previous calibration indefinitely
• Verify calibration or recalibrate in the new environment and update records
• Ignore calibration and continue experiments
• Only inform the vendor

Correct Answer: Verify calibration or recalibrate in the new environment and update records

Q29. Which parameter is NOT typically part of calibration traceability chain?

• Reference standard with known uncertainty
• Unbroken chain of calibrations linking to national standards
• Calibration technician’s favorite instrument color
• Calibration certificates and dates

Correct Answer: Calibration technician’s favorite instrument color

Q30. Why is routine performance verification between formal calibrations recommended?

• To decorate the lab
• To detect drift or sudden faults early and ensure ongoing measurement quality
• Because calibration is always invalid
• To avoid having any calibration records

Correct Answer: To detect drift or sudden faults early and ensure ongoing measurement quality

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