Science and Technology as a GK topic for SSC CGL is not a single, unified subject — it is a sprawling collection of facts drawn from at least six distinct domains: space exploration, defence and weaponry, computing and IT, biotechnology, climate science, and scientific instruments. The exam treats this chapter as a factual repository, not a conceptual one. The questions rarely ask "why does this work?" They ask "what is this called?", "when was it first used?", or "which organisation manages this?"
Think of it this way: if General Science (Physics, Chemistry, Biology) is the classroom, then Science and Technology is the newspaper reading room next door. It is applied, current, and institution-heavy.
Here is what distinguishes this topic from others in the GK section. Unlike History or Polity, where topics cluster around a few major events or Articles, S&T questions can appear from almost any year or domain. A question from 2013 about daisy-wheel printing sits beside a 2025 question about ISRO's solar observatory. The breadth is real — you cannot predict the exact question. But you can predict the categories the question will fall into, and that is your leverage point.
The analogy that helps: treat this topic like a metro map. You do not memorise every building in Delhi — you memorise which station connects to which line, and which stations are interchange points. In S&T, your interchange stations are the big institutions — ISRO, DRDO, CSIR, NASA partnerships, the UN's science bodies — because they anchor the most questions. Individual missions, instruments, and inventors hang off those nodes.
SSC CGL has historically drawn S&T questions from three recurring bands:
Know these three bands cold, and you cover roughly 70% of the S&T questions that have appeared in CGL tier-1 over the last decade.
ISRO questions in recent years cluster around mission objectives, insertion orbits, and firsts. Look at the pattern:
Aditya-L1: India's first solar observatory, placed at the Sun-Earth Lagrange Point 1 (L1). Its primary job is studying the solar corona — the outermost, hottest layer of the Sun — and understanding why the corona is far hotter than the photosphere below it. Secondary instruments study solar wind, solar flares, and CMEs (Coronal Mass Ejections). Do not confuse it with Chandrayaan or Mangalyaan — Aditya is Sun-facing, stationed at L1 roughly 1.5 million km from Earth.
PSLV-C59 / Proba-3 (2024): ISRO's PSLV launched the European Space Agency's Proba-3 twin-satellite mission. The unique element here is formation flying — two satellites maintaining a precise formation in space to artificially create a solar eclipse, allowing scientists to study the solar corona from Earth orbit. This was a milestone in India-ESA cooperation. Questions on this test whether you know: (a) the launcher (PSLV-C59), (b) the payload (ESA's Proba-3), (c) the purpose (formation flying / corona study).
Gaganyaan and the Crew Escape System (CES): India's human spaceflight programme. The CES is the safety net — if the launch vehicle malfunctions during ascent, solid motors rapidly pull the crew module away from the rocket. Parachutes then handle controlled descent. The system activates automatically through the Integrated Vehicle Health Management (IVHM) system. Key contrast: liquid fuel versus solid motors. The CES uses solid motors — faster response, more reliable in an emergency. Liquid-fuel ejectors are a distractor answer.
The computing questions in CGL have a predictable vintage (2010–2016) and a predictable question type: "which was the first X?"
When CGL gives you a printing question, the first filter is: impact or non-impact? Daisy wheel and dot-matrix are impact. Inkjet and laser are non-impact.
These questions test a simple mapping: instrument → what it measures.
| Instrument | Measures | |---|---| | Anemometer | Wind speed / speed of gas current | | Barometer | Atmospheric pressure | | Hygrometer | Humidity | | Seismograph | Seismic waves / earthquake intensity | | Lactometer | Purity of milk | | Manometer | Gas / fluid pressure | | Tachometer | Rotation speed |
For SSC CGL, the anemometer, barometer, and lactometer appear most frequently. The key phrase for anemometer: "speed of wind, or of any current of gas" — the "or of any current of gas" part trips up students who only remember "wind speed."
A state of matter predicted by Satyendra Nath Bose and Albert Einstein. In 1995, Eric Cornell and Carl Wieman experimentally produced it in rubidium atoms cooled to near absolute zero. They received the Nobel Prize in Physics in 2001. Cornell's Nobel Lecture was on December 8, 2001 at Aula Magna, Stockholm University — note the date is the 8th, not the 10th (the Nobel ceremony date). This is a precise factual trap.
Lagrange points have a pattern: L1 sits between the Earth and the Sun, so it is perfect for solar observation — Aditya-L1 goes there. L2 sits behind Earth (away from the Sun), ideal for deep-space telescopes shielded from solar interference — James Webb Telescope goes there. One rule: L1 = Sun-facing, L2 = space-facing. This lets you eliminate three wrong options instantly when a question asks about Aditya's location. Standard method: read and recall each option (~30s). With this pattern: eliminate L2, L4, L5 in one step (~8s).
Chain the three facts: U-C-1951. UNIVAC → Census Bureau → 1951. ENIAC was earlier (1945) but not commercial. EDSAC was British. MANIAC was Los Alamos research. If the question says "first commercial," you do not need to recall a date — UNIVAC is the only option that was commercially delivered. Eliminates three distractors in one pass. Standard method: recall all four machines and their dates (~40s). With this pattern: anchor on "commercial" → UNIVAC, done (~6s).
Impact printing technologies physically strike the paper through an ink ribbon — think typewriter. Daisy wheel, dot-matrix = impact. Inkjet, laser, thermal = non-impact. When you see a printing question, the first word you look for in each option is "impact" or "non-impact." If the question involves daisy wheel, the correct option must contain "impact." Eliminates inkjet and laser options immediately. Reduces a 4-option question to a 2-option question in under 5 seconds, versus reading all four options fully (~20s).
IPCC questions always include a trap option calling it "a research organisation" or "a US/World Bank body." Use a two-word filter: "intergovernmental" and "UN." If an option lacks both words, eliminate it. The correct answer will always say "under the auspices of the United Nations" and "scientific and intergovernmental." This two-word test collapses a definitional question to a single pass. Standard method: read all four definitions (~35s). With this filter: locate "UN + intergovernmental" (~10s).
The Crew Escape System question is a distractor minefield: water parachutes, liquid fuel ejectors, airbags — none are correct. The operative word is "solid motors" and the operative action is "pull away" (not push, not eject). Solid motors are fast-acting and reliable — critical for an emergency abort. Memorise the phrase: "solid motors pull the crew module away." Four words. In the exam, scan each option for "solid" and "pull." If neither is present, eliminate. Reduces 4 options to 1 in approximately 8 seconds versus evaluating each technical description (~45s).
When you see an S&T question in the exam hall, run this three-step filter:
Step 1 — Category ID (5 seconds): Is this about (a) a space mission, (b) a computing/printing device, (c) a scientific instrument, (d) a climate/international body, or (e) a state-of-matter / physics phenomenon? Your category determines your memory cluster.
Step 2 — Anchor Word (5 seconds): Identify the anchor word or phrase in the question — "first commercial," "primary objective," "measures wind speed," "intergovernmental," "solid motors." That anchor word should immediately activate the correct fact cluster.
Step 3 — Trap Elimination (10 seconds): S&T questions are trap-heavy. Before confirming your answer, check: is there a "sounds right but wrong" option? Common traps — ENIAC instead of UNIVAC, L2 instead of L1, "liquid fuel" instead of "solid motors," "research organisation" instead of "intergovernmental body." Eliminate the trap first, then confirm your choice.
Total time target: under 30 seconds for a straightforward S&T question, under 60 seconds for an assertion-reason type.
Why this question: Aditya-L1 is the most high-yield recent ISRO mission. Any CGL paper from 2024 onwards will reference it or Chandrayaan-3. You need the precise objective language.
Solving path: The question asks for "primary objective." Anchor word: "corona." Moon's surface — eliminate (that is Chandrayaan). Earth's climate — eliminate (that is a satellite like INSAT). Distant galaxies — eliminate (that is a deep-space telescope). Solar atmosphere / corona — correct. The corona is the Sun's outermost, hottest layer. Aditya sits at L1 specifically to study it. Time: under 15 seconds.
Why this question: Assertion-reason format tests two facts simultaneously. PSLV-C59 and Proba-3 represent the India-ESA cooperation angle, which CGL has started testing heavily since 2022.
Solving path: Verify A — did PSLV-C59 achieve a milestone for international cooperation? Yes, it launched ESA's satellite. Verify R — did it deploy Proba-3 for a formation-flying experiment? Yes. Now check: does R explain A? The milestone in A is the international cooperation; R explains exactly what that cooperation was (deploying ESA's Proba-3). Both true, R correctly explains A. Option C.
Why this question: Gaganyaan-related questions will dominate the next two to three years of SSC papers. The CES is a specific technical component that has already appeared and will appear again.
Solving path: Eliminate water parachutes (parachutes come after the CES activates, not during). Eliminate liquid fuel ejectors (wrong mechanism). Eliminate airbags (no such system in CES). The correct mechanism: solid motors rapidly pull the crew module away. "Rapidly pulling... using solid motors" — this is option C. Time: 20 seconds.
Why this question: Instrument-mapping questions are among the fastest marks in the GK section — one fact, one answer. Anemometer appears repeatedly across CGL years.
Solving path: Anemometer = wind speed or speed of any gas current. This is the full definition — note "or any current of gas" extends beyond just wind. Options for light intensity (photometer), water depth (fathometer), and sound speed (all different instruments) are straightforward eliminations. Time: 10 seconds.
Why this question: Computing history questions from the 2011–2016 era still recycle. UNIVAC vs ENIAC is the classic trap — both are early computers, but only one was the first commercially available machine.
Solving path: The key phrase is "commercial use." ENIAC (1945) was a research machine, not sold commercially. MANIAC and EDSAC were research machines. UNIVAC was delivered commercially to the US Census Bureau in 1951. If you remember "U-C-1951" (UNIVAC → Census → 1951), this is a 10-second question.
Confusing Aditya-L1's orbit location with its objective. Students who know L1 sometimes say the objective is "to stay at Lagrange Point 1" — that is the method, not the objective. The objective is studying the solar corona and solar atmosphere. Always frame objective as what it studies, not where it parks.
Mixing up ENIAC and UNIVAC. ENIAC was earlier (1945) and was the first general-purpose electronic computer, but it was not commercially sold. UNIVAC was the first commercially available computer (1951). The question will always specify "commercial use" — anchor on that phrase.
Calling IPCC a research organisation. The IPCC does not conduct its own experiments or field studies. It synthesises and assesses existing research. If an exam option says "research organisation," it is wrong. The correct framing is "scientific and intergovernmental body" under UN auspices.
Confusing impact and non-impact printing. Daisy wheel is impact (physical strike). Inkjet is non-impact (liquid droplets). The exam's distractor options for daisy wheel always include "inkjet technology" or "non-impact technology invented by IBM." The IBM clue is also a trap — daisy wheel was invented at Diablo Data Systems, not IBM.
Getting the Cornell Nobel Lecture date wrong. The Nobel Prize ceremony is December 10. Cornell's lecture was December 8, 2001. This two-day difference is the trap — the exam specifically asked for the lecture date, not the ceremony date. If you conflate "Nobel Lecture" with "Nobel Prize Day," you pick the 10th and lose the mark.
Assuming the Crew Escape System uses liquid propellants. Liquid motors are used in main launch vehicles for controllable thrust. Emergency abort systems use solid motors — they ignite instantly, require no ignition sequence, and are far more reliable under anomaly conditions. "Solid motors" and "pull away" are the two non-negotiable facts for CES.