7.3 General Science Fundamentals & Military/Defense GK

7.3 General Science and Military General Knowledge

Study method: Separate stable concepts from changing officeholders and counts. Learn units, relationships, and rank equivalence permanently; verify current command appointments near the examination date.

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SI Units and Basic Physics

The seven SI base quantities and units are:

Derived units follow from equations. Force is measured in newtons: one newton equals one kilogram metre per second squared. Work and energy are measured in joules, with one joule equal to one newton metre. Power is the rate of energy transfer and is measured in watts, or joules per second. Pressure is force per area and is measured in pascals, or newtons per square metre. Frequency uses hertz, meaning cycles per second. Electric charge uses coulombs, potential difference volts, and resistance ohms.

When a multiple-choice item mixes units, identify the requested quantity before calculating. Joules cannot answer a power question without a time term, and pascals cannot answer an energy question. Dimensional checking catches many distractors.

Solar System

The planet order from the Sun is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. A useful pattern is four inner rocky planets followed by four outer giant planets. The asteroid belt lies mainly between Mars and Jupiter and contains many objects; Ceres is the largest object in that belt and is classified as a dwarf planet.

• Mercury is closest to the Sun and is the smallest planet.
• Venus has a dense carbon-dioxide atmosphere and the highest average surface temperature of any planet.
• Earth is the third planet and the only world known to support life.
• Mars appears red because of iron oxides and has Phobos and Deimos.
• Jupiter is the largest planet; Ganymede is the largest moon in the Solar System.
• Saturn is noted for its conspicuous ring system and low mean density.
• Uranus has an extreme axial tilt and appears blue-green because of methane.
• Neptune is the farthest major planet and has very fast atmospheric winds.

Do not memorize a fixed current moon count for Jupiter or Saturn: new discoveries and confirmations change totals. Pluto was reclassified as a dwarf planet by the International Astronomical Union in 2006 because it does not clear its orbital neighborhood.

Atmosphere and Human Biology

From the surface upward, the main atmospheric layers are troposphere, stratosphere, mesosphere, thermosphere, exosphere. Most weather occurs in the troposphere. The stratosphere contains the ozone-rich region that absorbs much ultraviolet radiation. Many meteors become visible and disintegrate in the mesosphere. Auroras occur mainly in the upper atmosphere, especially the thermosphere/ionosphere region. The exosphere grades into space.

The heart has four chambers. Deoxygenated blood returns to the right atrium, moves to the right ventricle, and is pumped through pulmonary arteries to the lungs. Oxygenated blood returns through pulmonary veins to the left atrium, moves to the left ventricle, and leaves through the aorta. The pulmonary artery and vein are common exam traps because their names follow direction relative to the heart, not oxygen content.

For red-cell transfusion shorthand, O-negative is called the universal donor type because its red cells lack A, B, and RhD antigens; AB-positive is called the universal red-cell recipient type. This is an exam-level simplification. Actual transfusion practice uses blood typing, antibody screening, crossmatching, and clinical judgment, so no blood product should be described as automatically safe for everyone.

High-frequency deficiency pairs include vitamin A and night blindness, B1 and beriberi, B3 and pellagra, C and scurvy, D and rickets/osteomalacia, and K and impaired clotting. Link each vitamin to a function: vitamin D supports calcium metabolism and bone mineralization; vitamin C supports collagen; vitamin K supports clotting-factor activation.

Pakistan Armed Forces Command Structure

Article 243 of Pakistan's Constitution places federal control and command over the Armed Forces and vests supreme command in the President. The 2025 constitutional change provides for appointment of the Chief of the Army Staff concurrently as Chief of Defence Forces, alongside the Chief of the Naval Staff and Chief of the Air Staff. It abolished the office of Chairman, Joint Chiefs of Staff Committee with effect from 27 November 2025 and provided for a Commander of the National Strategic Command.

As of this section's update, official Presidency material identifies Field Marshal Syed Asim Munir as COAS and concurrently Chief of Defence Forces. Personal officeholder questions are time-sensitive and should be checked from official government or service sources immediately before the test.

Tri-Service Rank Equivalence

The safest way to learn equivalence is by rows. An Army Captain corresponds to a Navy Lieutenant and PAF Flight Lieutenant; an Army Major corresponds to a Navy Lieutenant Commander and PAF Squadron Leader.

Nishan-e-Haider

Nishan-e-Haider is Pakistan's highest military gallantry award. Standard national references count eleven honorees when Naik Saif Ali Janjua's Hilal-e-Kashmir—later declared equivalent—is included. Pilot Officer Rashid Minhas is the youngest honoree and the only Pakistan Air Force member in that roll; the others are associated with the Army or Azad Kashmir forces in the standard list.

For revision, focus on the stable pairings often tested: Captain Muhammad Sarwar as the first Nishan-e-Haider recipient; Major Raja Aziz Bhatti with the 1965 war; Major Muhammad Akram, Major Shabbir Sharif, Sawar Muhammad Hussain, Lance Naik Muhammad Mahfuz, and Rashid Minhas with 1971; and Captain Karnal Sher Khan and Havildar Lalak Jan with the 1999 Kargil conflict. Avoid sensational or overly detailed battle narratives unless studying from an official citation.