NDA General Ability Test (GAT)
Why This Chapter Matters
GAT is worth 600 marks in NDA (Paper II) — double the Mathematics paper. It covers English (200 marks) and General Knowledge (400 marks). GK covers Physics, Chemistry, General Science, History, Geography, Civics, and Current Events.
Part A — English (200 marks)
Grammar Topics Tested
Vocabulary
Synonyms, Antonyms, One-word substitution, Idioms and phrases
Comprehension
Reading passages with inference, main idea, and vocabulary questions.
Key Grammar Rules for NDA
Voice (Active to Passive):
Active: Subject + Verb + Object
Passive: Object + be(tense) + past participle + by + Subject
Active: "The teacher teaches mathematics."
Passive: "Mathematics is taught by the teacher."
Narration (Direct to Indirect):
Statement: Say/said that + tense shift back
"He said, 'I am happy.'" → "He said that he was happy."
Command: tell/ask + to + infinitive
Question: ask/enquire if/whether
Part B — General Knowledge (400 marks)
Section A: Physics
Key topics:
Important facts:
Speed of light: 3×10^8 m/s
Speed of sound in air: 343 m/s (at 20°C)
Ultrasound frequency: >20,000 Hz
Human hearing range: 20 Hz to 20,000 Hz
Section B: Chemistry
Key topics:
Important facts:
Air composition: 78% N₂, 21% O₂, 0.03% CO₂, rest rare gases
Heaviest metal: Osmium | Lightest metal: Lithium
Most abundant element on Earth: Oxygen | In universe: Hydrogen
Section C: General Science (Biology)
Important diseases:
Malaria: Plasmodium (protozoa), Anopheles mosquito
Dengue: Virus, Aedes mosquito
Tuberculosis: Mycobacterium tuberculosis (bacteria)
Vitamin deficiency diseases: A(night blindness), B1(beriberi), C(scurvy), D(rickets)
Section D: History of India
Ancient India:
Indus Valley Civilisation (3300-1300 BCE): Harappa, Mohenjo-daro
Vedic Age: Rig Veda (oldest), Sama, Yajur, Atharva Vedas
Maurya Empire: Chandragupta Maurya, Ashoka (spread Buddhism)
Gupta Empire: "Golden Age" — Kalidasa, Aryabhata
Medieval India:
Delhi Sultanate (1206-1526): Slave Dynasty, Khilji, Tughlaq, Sayyid, Lodi dynasties
Mughal Empire (1526-1857): Babur, Humayun, Akbar, Jehangir, Shah Jahan (Taj Mahal), Aurangzeb
Modern India:
British rule: East India Company → Crown Rule (1858)
Freedom movement: Sepoy Mutiny (1857), Indian National Congress (1885), Non-Cooperation (1920), Civil Disobedience (1930), Quit India (1942)
Independence: 15 August 1947
Section E: Geography of India and World
India geography:
Area: 3.28 million sq km (7th largest country)
Borders: Pakistan (W), China/Nepal/Bhutan (N), Bangladesh/Myanmar (E)
Longest river: Ganga | Largest state: Rajasthan | Smallest state: Goa
Highest peak: Kangchenjunga (8586m, India's highest), K2 (Pakistan-China)
Climate: Monsoon climate. Southwest monsoon (June-Sep) — main agriculture season.
World geography:
Largest continent: Asia | Largest ocean: Pacific
Longest river: Nile | Deepest ocean point: Mariana Trench (Pacific)
Sahara: world's largest hot desert | Antarctica: world's largest cold desert
Section F: Current Events and Defence
Current events cover last 6 months: national/international news, sports, awards, science.
Defence-specific GK:
Indian Army motto: "Service Before Self"
Indian Navy motto: "Sam No Varunah"
Indian Air Force motto: "Touch the Sky with Glory" (Nabha Sparsham Diptam)
NDA location: Khadakwasla, Pune
Defence Research Development Organisation (DRDO): indigenously develops weapons
Chief of Defence Staff (CDS): Coordinates the three services.
Major defence systems: Agni missiles (ICBM), BrahMos (cruise missile), Tejas (fighter jet), INS Vikrant (aircraft carrier), Arjun MBT
PYQs (NDA GAT)
NDA 2023 (English): Fill the blank: "She has been working ___ five years."
Answer: for (duration → "for", specific start point → "since")
NDA 2022 (Physics): Ultrasonic waves are used in:
(A) SONAR (B) X-ray (C) EEG (D) ECG
Answer: A — SONAR (Sound Navigation And Ranging) uses ultrasound.
NDA 2021 (History): The battle of Plassey was fought in:
Answer: 1757 — marked beginning of British political power in India.
NDA 2020 (Geography): Which is the largest freshwater lake in India?
Answer: Wular Lake (Kashmir) — largest. Vembanad is largest in southern India.