AFCAT Science and Technology 2 — Questions and Answers
Question 1: Which phenomenon explains why the sky appears blue during the day?
- Reflection of sunlight by clouds
- Rayleigh scattering of sunlight by atmospheric molecules (Correct answer)
- Absorption of red wavelengths by ozone
- Refraction of light at the Earth's surface
Correct answer: Rayleigh scattering of sunlight by atmospheric molecules
Rayleigh scattering causes shorter blue wavelengths to scatter more than longer red wavelengths, making the sky appear blue.
Question 2: What is the primary fuel used in India's PSLV (Polar Satellite Launch Vehicle)?
- Liquid hydrogen and liquid oxygen
- Solid propellant (HTPB) in core stages with liquid engines (Correct answer)
- Aviation turbine fuel (ATF)
- Liquid methane and liquid oxygen
Correct answer: Solid propellant (HTPB) in core stages with liquid engines
PSLV uses solid propellant (HTPB-based) in its first and third stages, with liquid engines in the second and fourth stages.
Question 3: Which law states that the pressure of a fixed amount of gas at constant volume is directly proportional to its absolute temperature?
- Boyle's Law
- Charles's Law
- Gay-Lussac's Law (Correct answer)
- Avogadro's Law
Correct answer: Gay-Lussac's Law
Gay-Lussac's Law (P ∝ T at constant volume) describes the relationship between pressure and absolute temperature for a fixed gas sample.
Question 4: What does the term 'RADAR' stand for?
- Radio Amplification Detection And Ranging
- Radio Detection And Ranging (Correct answer)
- Rapid Aerial Detection And Ranging
- Remote Aerial Detection And Ranging
Correct answer: Radio Detection And Ranging
RADAR stands for Radio Detection And Ranging, a system that uses radio waves to detect and locate objects.
Question 5: Which type of electromagnetic radiation has the highest frequency?
- X-rays
- Ultraviolet rays
- Gamma rays (Correct answer)
- Microwaves
Correct answer: Gamma rays
Gamma rays have the highest frequency (and shortest wavelength) in the electromagnetic spectrum.
Question 6: What is the SI unit of electric capacitance?
- Henry
- Tesla
- Farad (Correct answer)
- Ohm
Correct answer: Farad
The farad (F) is the SI unit of electric capacitance, named after physicist Michael Faraday.
Question 7: Which satellite navigation system is developed and operated by India?
- GLONASS
- NavIC (IRNSS) (Correct answer)
- Galileo
- BeiDou
Correct answer: NavIC (IRNSS)
NavIC (Navigation with Indian Constellation), also known as IRNSS, is India's indigenous regional satellite navigation system operated by ISRO.
AFCAT Science and Technology 2
Which phenomenon explains why the sky appears blue during the day?