A Textbook for Pharmacy Students and Pharmaceutical Chemists
Author : David G. Watson
,Pharmaceutical Analysis, 5th Edition — Chapter 1: Control of the Quality of Analytical
Methods.
MCQs (1–30)
SECTION A: THEORY-BASED (1–15)
1. Which term describes the closeness of measured values to the true value?
A. Precision
B. Accuracy
C. Sensitivity
D. Specificity
Correct Answer: B. Accuracy
Explanation:
• Accuracy = closeness to the true/accepted value.
• Precision = reproducibility, not correctness.
Why others are wrong:
• A: Precision = consistency, not correctness
• C: Sensitivity = ability to detect small changes
• D: Specificity = ability to measure analyte in presence of others
Practical Insight: In drug assay, high accuracy ensures correct dosage labeling.
2. Precision is best defined as:
A. Closeness to true value
B. Repeatability of measurements
C. Detection limit
D. Selectivity
Answer: B
,Explanation:
Precision reflects reproducibility under unchanged conditions.
Incorrect:
• A = accuracy
• C = sensitivity
• D = specificity
Lab Context: High precision is critical in repeated batch testing.
3. Which parameter reflects the ability to detect small concentrations?
A. Specificity
B. Accuracy
C. Sensitivity
D. Precision
Answer: C
Explanation:
Sensitivity = slope of calibration curve.
Incorrect:
• A: interference handling
• B: correctness
• D: repeatability
4. The Beer-Lambert law relates absorbance to:
A. Temperature
B. Concentration
C. Pressure
D. pH
Answer: B
, Explanation:
Absorbance ∝ concentration.
5. Which equation represents Beer-Lambert law?
A=εbcA = \varepsilon b cA=εbc
A. A = εbc
B. A = mc²
C. PV = nRT
D. E = hf
Answer: A
Explanation:
• A = absorbance
• ε = molar absorptivity
• b = path length
• c = concentration
Others: unrelated physics equations.
6. Specificity refers to:
A. Sensitivity to low concentrations
B. Ability to measure analyte without interference
C. Repeatability
D. Calibration
Answer: B
7. Which is NOT a source of analytical error?
A. Instrumental error
B. Personal error