CMSP Fundamental Knowledge of Science 4 — Questions and Answers
Question 1: Which physical principle is used by miners' self-rescuers (SCSRs) to generate breathable oxygen?
- Electrolysis of water
- Chemical reaction of potassium superoxide (KO₂) with moisture and CO₂ (Correct answer)
- Compressed oxygen released through a pressure regulator
- Catalytic decomposition of hydrogen peroxide
Correct answer: Chemical reaction of potassium superoxide (KO₂) with moisture and CO₂
SCSRs use potassium superoxide (KO₂) which reacts with exhaled moisture and CO₂ to release oxygen and absorb carbon dioxide.
Question 2: Rock mechanics in mining defines 'stress' as:
- The total weight of overburden above a mine opening
- Force per unit area acting on a rock mass (Correct answer)
- The deformation of rock relative to its original length
- The energy stored per unit volume in compressed rock
Correct answer: Force per unit area acting on a rock mass
Stress (σ) = Force ÷ Area; it is an internal force per unit area within a rock mass, distinct from strain which is deformation.
Question 3: Which wavelength range of electromagnetic radiation is classified as ultraviolet (UV)?
- 700–1000 nm
- 400–700 nm
- 10–400 nm (Correct answer)
- 1–10 nm
Correct answer: 10–400 nm
Ultraviolet radiation spans approximately 10–400 nm, shorter than visible light (400–700 nm) and relevant to arc welding hazards in mines.
Question 4: What is the approximate percentage of oxygen in normal atmospheric air at the surface?
- 15%
- 21% (Correct answer)
- 25%
- 78%
Correct answer: 21%
Normal atmospheric air contains approximately 20.9% (≈21%) oxygen, 78% nitrogen, and 1% argon and other gases.
Question 5: In chemistry, which term describes a substance that donates protons (H⁺) in a chemical reaction?
- Base
- Acid (Correct answer)
- Buffer
- Salt
Correct answer: Acid
According to the Brønsted-Lowry definition, an acid is a proton (H⁺) donor, relevant to understanding acid mine drainage chemistry.
Question 6: The decibel (dB) scale for measuring sound is based on which mathematical relationship?
- Linear scale relative to atmospheric pressure
- Logarithmic scale relative to a reference sound pressure (Correct answer)
- Exponential scale relative to the pain threshold
- Square root scale relative to ambient noise
Correct answer: Logarithmic scale relative to a reference sound pressure
The decibel scale is logarithmic: dB = 20 × log₁₀(P/P₀), where P₀ is the reference sound pressure of 20 μPa.
Question 7: Which property of water makes it an effective medium for fire suppression in underground mines?
- High electrical conductivity allowing current to carry heat away
- High specific heat capacity and latent heat of vaporization absorbing large amounts of energy (Correct answer)
- Low viscosity allowing it to penetrate coal seams rapidly
- High chemical reactivity with burning carbon compounds
Correct answer: High specific heat capacity and latent heat of vaporization absorbing large amounts of energy
Water's high specific heat (4.18 J/g·°C) and very high latent heat of vaporization (2,260 J/g) allow it to absorb enormous amounts of thermal energy when suppressing fires.
CMSP Fundamental Knowledge of Science 4
Which physical principle is used by miners' self-rescuers (SCSRs) to generate breathable oxygen?