8.3 National & Global General Knowledge, Basic Science & Current Facts

Pakistan Geography, Boundaries & National Symbols

A substantial portion of the PAF Airman academic examination evaluates general knowledge regarding Pakistan's physical geography, international borders, national insignia, and civic history.

Geography and International Land Borders

Pakistan is situated in South Asia, spanning a total land area of approximately 881,913 square kilometers (including Azad Jammu & Kashmir and Gilgit-Baltistan). Pakistan shares land borders with four sovereign nations and has a coastline along the Arabian Sea:

Key Physical Features

• Highest Mountain Peak: K2 (Mount Godwin-Austen) at 8,611 meters (28,251 ft), located in the Karakoram Range, Gilgit-Baltistan. It is the second-highest peak in the world.
• Longest River: Indus River (Darya-e-Sindh), originating near Lake Manasarovar in Tibet, stretching approximately 3,180 kilometers before emptying into the Arabian Sea.
• Largest Desert: Thar Desert (stretching into Sindh and Punjab as the Cholistan Desert).

Official National Symbols of Pakistan

Principles of Aviation Physics & Basic Science

Candidates taking technical trade tests (such as Aero-Trade and Avionics) are tested on high-school level physics, atmospheric chemistry, and aeronautical mechanics.

Aerodynamics and Flight Mechanics

Four fundamental forces act upon an aircraft during flight:

1. Lift: Upward aerodynamic force created by air pressure differences across the wing wings (airfoil).
2. Weight (Gravity): Downward force pulling the aircraft toward Earth's center.
3. Thrust: Forward force generated by aircraft engines (propellers or jet turbines).
4. Drag: Rearward retarding force caused by atmospheric air resistance.

              ↑ LIFT
              │
  THRUST ◄────┼────► DRAG
              │
              ↓ WEIGHT

Bernoulli's Principle

Bernoulli's Principle states that as the speed of a moving fluid or gas (air) increases, the internal pressure within that fluid decreases.
An aircraft wing (airfoil) is designed with a curved upper surface (camber) and a flat lower surface. Air traveling over the top of the wing moves faster than air underneath. According to Bernoulli's principle, the faster-moving air above creates a lower pressure area, while the slower-moving air below creates higher pressure, generating the net upward force called Lift.

Speed of Sound and Mach Numbers

• Speed of Sound (at Sea Level, 20°C): Approximately 343 meters per second ($343\text{ m/s}$), equivalent to 1,235 km/h or 761 mph or 661 knots.
• Mach Number: Ratio of an object's speed to the speed of sound in the surrounding gas.
  $\text{Mach Number} = \frac{v_{\text{aircraft}}}{v_{\text{sound}}}$
  • Subsonic: Mach $< 1.0$
  • Transonic: Mach $\approx 1.0$
  • Supersonic: Mach $1.0 - 5.0$ (e.g., JF-17 top speed is Mach 1.6)
  • Hypersonic: Mach $> 5.0$

Atmospheric Composition & Measurement Units

• Dry Air Composition: 78% Nitrogen ($\text{N}_2$), 21% Oxygen ($\text{O}_2$), 0.93% Argon ($\text{Ar}$), and 0.04% Carbon Dioxide ($\text{CO}_2$).
• Nautical Mile (NM): Standard aviation unit of distance. $1\text{ NM} = 1.852\text{ kilometers} = 1.151\text{ statute miles}$.
• Knot (kt): Unit of speed equal to one nautical mile per hour ($1\text{ knot} = 1.852\text{ km/h}$). collapse

International Organizations & Global Facts

General knowledge questions in PAF selection tests frequently cover major international bodies, treaty organizations, geographic superlatives, and global scientific landmarks.

Key International Organizations

World Geography & Science Superlatives

• Largest Continent by Area & Population: Asia (covers ~30% of Earth's land area).
• Largest Ocean: Pacific Ocean (covers over 30% of Earth's surface; deepest point is the Mariana Trench at approximately 11,000 meters / 36,000 feet deep).
• Speed of Light in Vacuum: Approximately $3 \times 10^8\text{ meters per second}$ ($300,000\text{ km/s}$).
• SI Unit of Force: Newton (N) ($1\text{ N} = 1\text{ kg}\cdot\text{m/s}^2$).
• SI Unit of Pressure: Pascal (Pa) ($1\text{ Pa} = 1\text{ N/m}^2$). Aviation altimeters often use hectopascals (hPa) or millibars (mbar) ($1013.25\text{ hPa}$ standard sea level pressure).