Yield calculation and limits MCQs With Answer

Introduction

This quiz collection on yield calculation and limits is designed specifically for M.Pharm students studying Quality Control and Quality Assurance. It focuses on practical and theoretical aspects of yield determination across pharmaceutical manufacturing — including theoretical yield, actual yield, percent yield, adjustments for potency and moisture, multi‑step cumulative yields, and documenting yield limits. Emphasis is placed on calculations you will perform in batch records, the regulatory rationale behind setting yield limits, and common sources of discrepancies (transfer losses, assay variations, drying). Working through these MCQs will strengthen your ability to calculate, interpret, and justify yields in a GMP environment.

Q1. What is the correct formula for calculating percent yield?

• Theoretical yield / Actual yield × 100
• Actual yield / Theoretical yield × 100
• Actual yield − Theoretical yield
• Actual yield / Batch size × 100

Correct Answer: Actual yield / Theoretical yield × 100

Q2. How is the theoretical yield best defined in pharmaceutical manufacturing?

• The maximum amount of product expected based on formulation, stoichiometry and starting material purity
• The minimum acceptable amount of product after losses
• The actual amount obtained from production
• The declared pack weight including packaging

Correct Answer: The maximum amount of product expected based on formulation, stoichiometry and starting material purity

Q3. If an active pharmaceutical ingredient has an assay of 90%, how should the theoretical yield be adjusted?

• Multiply the theoretical yield by 1.10
• Multiply the theoretical yield by 0.90
• Divide the theoretical yield by 0.90
• No adjustment is required for assay

Correct Answer: Multiply the theoretical yield by 0.90

Q4. What is the definition of actual yield?

• The calculated maximum product from raw materials
• The weight or amount of finished product obtained after processing
• The manufacturer’s declared batch size
• The loss recorded during processing

Correct Answer: The weight or amount of finished product obtained after processing

Q5. Which expression gives percent loss during production?

• (Actual − Theoretical) / Actual × 100
• (Theoretical − Actual) / Theoretical × 100
• Actual / Theoretical × 100
• Theoretical / Actual × 100

Correct Answer: (Theoretical − Actual) / Theoretical × 100

Q6. Which manufacturing issue most directly reduces apparent yield by reducing product weight?

• Higher than expected assay (potency)
• Excess water content subsequently lost during drying
• Use of over‑potent starting material
• Packaging slip that increases gross weight

Correct Answer: Excess water content subsequently lost during drying

Q7. What is the primary purpose of defining yield limits in a master batch record?

• To control colouring and odour of the product
• To provide target ranges that detect process deviations, losses or diversion
• To set the selling price of the batch
• To determine equipment cleaning intervals

Correct Answer: To provide target ranges that detect process deviations, losses or diversion

Q8. How do you compute the cumulative yield for a three‑step process with step yields of 90%, 95% and 98%?

• Add the three percentages and divide by three
• Multiply the fractional yields: 0.90 × 0.95 × 0.98 and convert to percent
• Take the lowest single step yield (90%) as the cumulative yield
• Use the average of the two highest yields

Correct Answer: Multiply the fractional yields: 0.90 × 0.95 × 0.98 and convert to percent

Q9. To report yield expressed as drug substance amount considering assay, which calculation is correct?

• Product weight × (assay % / 100)
• Product weight / (assay % / 100)
• Theoretical yield × assay %
• Assay % − product weight

Correct Answer: Product weight × (assay % / 100)

Q10. Which statement correctly describes net yield?

• Net yield includes the weight of packaging and labels
• Net yield is the product weight excluding packaging and non‑product materials
• Net yield is always greater than gross yield
• Net yield refers to the volume of solvent recovered

Correct Answer: Net yield is the product weight excluding packaging and non‑product materials

Q11. If an assay result is greater than 100% relative to label claim, what is the effect on calculated yield (all else equal)?

• Calculated yield decreases
• Calculated yield remains unchanged
• Calculated yield increases proportionally to the assay
• Calculated yield becomes invalid and cannot be used

Correct Answer: Calculated yield increases proportionally to the assay

Q12. Who is primarily responsible for establishing and approving yield limits in GMP documentation?

• Production operator without review
• Quality Assurance in consultation with Production and Quality Control
• Packaging vendor
• Sales department

Correct Answer: Quality Assurance in consultation with Production and Quality Control

Q13. How is yield loss typically expressed when documenting a discrepancy?

• As a volume (mL) only
• As a percentage of theoretical yield
• As a time delay in production
• As number of failed units only

Correct Answer: As a percentage of theoretical yield

Q14. If a formulation requires 100 g of API at 100% purity but the available API is 80% pure, what mass of API must be weighed in?

• 80 g
• 100 g
• 125 g
• 180 g

Correct Answer: 125 g

Q15. Why is yield reconciliation performed after production?

• To calculate employee productivity bonuses only
• To detect material discrepancies, prevent diversion and document process performance
• To set future selling prices
• To determine cleaning schedules

Correct Answer: To detect material discrepancies, prevent diversion and document process performance

Q16. A batch had a theoretical yield of 1000 g and an actual reported finished product weight of 950 g. What is the percent yield?

• 90%
• 95%
• 105%
• 100%

Correct Answer: 95%

Q17. A wet granule batch weighed 1,100 g before drying and the final product moisture loss is 10% w/w. What is the dry product weight after drying?

• 1,210 g
• 990 g
• 100 g
• 1,000 g

Correct Answer: 990 g

Q18. In granulation and tableting, which of the following is a common operational cause of low batch yield?

• Incomplete transfer of material between equipment and loss during handling
• Excessive ambient lighting in the plant
• Use of automated weight checks
• Appropriate cleaning validation

Correct Answer: Incomplete transfer of material between equipment and loss during handling

Q19. What information should be included in the batch record when reporting yield?

• Only the final percent yield with no calculations
• Gross and net weights, assay adjustments, calculation steps and units
• Only operator initials
• The selling price of the batch

Correct Answer: Gross and net weights, assay adjustments, calculation steps and units

Q20. Regulatory expectation regarding specification of yield and yield limits is that they must be:

• Arbitrarily set by production staff
• Scientifically justified, documented in the master batch record and approved by QA
• Kept confidential from inspectors
• Changed each batch without rationale

Correct Answer: Scientifically justified, documented in the master batch record and approved by QA

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