Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. Which law states that at constant pressure, the volume of a gas is
directly proportional to its absolute temperature?
A. Boyle’s Law
B. Charles’ Law
C. Dalton’s Law
D. Henry’s Law
Charles’ Law relates volume and absolute temperature at
constant pressure.
2. A cyclone in an air-sampling train is used primarily to:
A. Increase flow rate
B. Separate respirable from non-respirable particles
C. Collect vapors
D. Measure air velocity
Cyclones are used to size-select airborne particles, isolating the
respirable fraction.
3. The unit “sievert” (Sv) is used to measure:
A. Noise exposure
B. Radiation dose equivalent
C. Heat stress index
, D. Particulate concentration
Sievert quantifies biological effect of ionizing radiation on tissue.
4. Which control method is considered the first line of defense in
hazard control?
A. Personal protective equipment
B. Administrative controls
C. Engineering controls
D. Elimination of hazard
Engineering controls are preferred because they remove or
isolate the hazard before relying on human behavior.
5. The term NOAEL stands for:
A. Lethal dose for 50% of population
B. Threshold Limit Value
C. No-Observed-Adverse-Effect Level
D. Permissible Exposure Limit
NOAEL is the highest exposure at which no adverse effect is
observed.
6. Which of the following is the OSHA Action Level for occupational
noise exposure (8-hour TWA) triggering a hearing conservation
program?
A. 85 dBA
B. 90 dBA
C. 95 dBA
D. 100 dBA
OSHA requires hearing conservation when exposures reach 85
dBA TWA.
, 7. In vapour sampling with personal pumps for organic compounds,
the typical sampling media is:
A. Cellulose filter
B. PVC filter
C. Activated charcoal tube
D. Impinger
Activated charcoal adsorbs organic vapors which are later
analyzed in a lab.
8. Which statistic best represents the midpoint of a data set?
A. Mean
B. Median
C. Mode
D. Standard deviation
The median splits the data set into two equal halves.
9. Which one is not a major category of stressors that a professional
industrial hygienist addresses?
A. Chemical
B. Physical
C. Biological
D. Financial
Industrial hygiene focuses on chemical, physical, biological (and
ergonomic) hazards—not financial ones.
10. The four classic steps of industrial hygiene are: anticipate,
recognise, evaluate, and control. Which comes second?
A. Anticipate
B. Recognise
C. Evaluate