AFCAT Science and Technology 4 — Questions and Answers
Question 1: What is the phenomenon where a sound wave's observed frequency changes due to the relative motion between source and observer?
- Interference
- Resonance
- Doppler Effect (Correct answer)
- Diffraction
Correct answer: Doppler Effect
The Doppler Effect describes the change in observed frequency of a wave when the source and observer are in relative motion.
Question 2: Which component of a jet engine compresses incoming air before it enters the combustion chamber?
- Turbine
- Nozzle
- Compressor (Correct answer)
- Diffuser
Correct answer: Compressor
The compressor draws in and pressurizes air before it enters the combustion chamber, increasing the efficiency of combustion.
Question 3: What does DNA stand for?
- Deoxyribose Nucleic Acid
- Deoxyribonucleic Acid (Correct answer)
- Diribonucleic Acid
- Deoxyribose Nitrogen Acid
Correct answer: Deoxyribonucleic Acid
DNA stands for Deoxyribonucleic Acid, the molecule that carries genetic information in living organisms.
Question 4: Which type of orbit keeps a satellite stationary relative to a point on Earth's surface?
- Low Earth Orbit (LEO)
- Medium Earth Orbit (MEO)
- Geostationary Orbit (GEO) (Correct answer)
- Polar Orbit
Correct answer: Geostationary Orbit (GEO)
Geostationary Orbit at approximately 35,786 km altitude allows a satellite to match Earth's rotation and remain fixed over one point.
Question 5: Which principle states that it is impossible to simultaneously know the exact position and momentum of a subatomic particle?
- Pauli Exclusion Principle
- Heisenberg Uncertainty Principle (Correct answer)
- Schrödinger's Wave Equation
- de Broglie's Hypothesis
Correct answer: Heisenberg Uncertainty Principle
Heisenberg's Uncertainty Principle states that the more precisely position is known, the less precisely momentum can be known, and vice versa.
Question 6: What is the hardest naturally occurring substance on Earth?
- Corundum
- Quartz
- Diamond (Correct answer)
- Topaz
Correct answer: Diamond
Diamond is the hardest naturally occurring substance, rating 10 on the Mohs hardness scale, and is composed of pure carbon in a cubic crystal structure.
Question 7: Which technology does 5G cellular networks primarily use for faster data transmission compared to 4G?
- Lower frequency bands exclusively
- Millimeter wave (mmWave) spectrum and massive MIMO (Correct answer)
- Satellite relay stations
- Fiber optic cables between handsets
Correct answer: Millimeter wave (mmWave) spectrum and massive MIMO
5G uses millimeter wave spectrum (24–100 GHz) and massive MIMO (multiple-input multiple-output) antenna arrays to achieve significantly faster data rates than 4G.
AFCAT Science and Technology 4
What is the phenomenon where a sound wave's observed frequency changes due to the relative motion between source and observer?