These essential MCQ questions are selected from the most important topics in UPSC Civil Services Prelims General Science 2026. Sections include Physics, Chemistry, Biology, Space and Satellite Technology, Defence Technology, Biotechnology, Nanotechnology and Science in Everyday Life as per the UPSC syllabus. For truely unlimited daily MCQ practice, visit Vooo AI Education.
🔭 UPSC General Science
1Chandrayaan-3 successfully landed on the Moon's South Pole in:
Answer: C — 2023
Chandrayaan-3 successfully landed on the Moon's South Pole on 23 August 2023, making India the first country to land near the lunar South Pole and the fourth country overall to achieve a soft lunar landing (after USA, USSR and China). The Vikram lander and Pragyan rover operated for one lunar day (14 Earth days). India celebrated 23 August as National Space Day.
Chandrayaan-3 successfully landed on the Moon's South Pole on 23 August 2023, making India the first country to land near the lunar South Pole and the fourth country overall to achieve a soft lunar landing (after USA, USSR and China). The Vikram lander and Pragyan rover operated for one lunar day (14 Earth days). India celebrated 23 August as National Space Day.
2mRNA vaccines (like COVID-19 vaccines) work by:
Answer: B — Teaching cells to produce a harmless viral protein
mRNA (messenger RNA) vaccines contain genetic instructions that teach the body's cells to produce a harmless piece of the target pathogen (e.g., the spike protein of SARS-CoV-2). The immune system recognises this protein as foreign, mounts a response and develops memory cells. The mRNA is quickly broken down — it does not enter the cell nucleus or alter DNA.
mRNA (messenger RNA) vaccines contain genetic instructions that teach the body's cells to produce a harmless piece of the target pathogen (e.g., the spike protein of SARS-CoV-2). The immune system recognises this protein as foreign, mounts a response and develops memory cells. The mRNA is quickly broken down — it does not enter the cell nucleus or alter DNA.
3The unit of radioactivity is:
Answer: C — Becquerel
The Becquerel (Bq) is the SI unit of radioactivity — one Becquerel equals one nuclear decay per second. The older unit is the Curie (Ci): 1 Ci = 3.7 × 10¹⁰ Bq. The Gray (Gy) measures absorbed radiation dose; the Sievert (Sv) measures equivalent dose (biological effect); the Roentgen measures exposure.
The Becquerel (Bq) is the SI unit of radioactivity — one Becquerel equals one nuclear decay per second. The older unit is the Curie (Ci): 1 Ci = 3.7 × 10¹⁰ Bq. The Gray (Gy) measures absorbed radiation dose; the Sievert (Sv) measures equivalent dose (biological effect); the Roentgen measures exposure.
4CRISPR-Cas9 technology is used for:
Answer: B — Gene editing
CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats) is a revolutionary gene editing technology that allows precise modification of DNA sequences. It acts like molecular scissors. Developed by Jennifer Doudna and Emmanuelle Charpentier (Nobel Prize in Chemistry 2020), it has applications in medicine (genetic disease treatment), agriculture (crop improvement) and research.
CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats) is a revolutionary gene editing technology that allows precise modification of DNA sequences. It acts like molecular scissors. Developed by Jennifer Doudna and Emmanuelle Charpentier (Nobel Prize in Chemistry 2020), it has applications in medicine (genetic disease treatment), agriculture (crop improvement) and research.
5The speed of sound is maximum in which medium?
Answer: D — Steel
Sound travels fastest in solids (e.g., steel: ~5,960 m/s), then liquids (water: ~1,480 m/s), then gases (air: ~343 m/s). Speed of sound = 0 in vacuum. Sound is a mechanical wave — the closer and more strongly bonded the molecules, the faster sound propagates. Temperature also affects speed: higher temperature → faster sound in gases.
Sound travels fastest in solids (e.g., steel: ~5,960 m/s), then liquids (water: ~1,480 m/s), then gases (air: ~343 m/s). Speed of sound = 0 in vacuum. Sound is a mechanical wave — the closer and more strongly bonded the molecules, the faster sound propagates. Temperature also affects speed: higher temperature → faster sound in gases.
6Nanotechnology involves working with materials at the scale of:
Answer: B — Nanometres (10⁻⁹ m)
Nanotechnology involves manipulating matter at the scale of 1-100 nanometres (10⁻⁹ metres). At this scale, materials exhibit unique physical and chemical properties. Applications include nano-medicines (targeted drug delivery), nano-composites (stronger lighter materials), nano-electronics, water purification membranes and sunscreens.
Nanotechnology involves manipulating matter at the scale of 1-100 nanometres (10⁻⁹ metres). At this scale, materials exhibit unique physical and chemical properties. Applications include nano-medicines (targeted drug delivery), nano-composites (stronger lighter materials), nano-electronics, water purification membranes and sunscreens.
7Stem cells are important in medicine because:
Answer: B — They can differentiate into various cell types
Stem cells are undifferentiated cells capable of self-renewal and differentiation into specialised cell types. Embryonic stem cells are pluripotent (can form any body cell). Adult stem cells are multipotent (limited range). Induced Pluripotent Stem Cells (iPSCs) are reprogrammed adult cells. Medical applications include treatment of blood disorders, spinal injuries and diabetes.
Stem cells are undifferentiated cells capable of self-renewal and differentiation into specialised cell types. Embryonic stem cells are pluripotent (can form any body cell). Adult stem cells are multipotent (limited range). Induced Pluripotent Stem Cells (iPSCs) are reprogrammed adult cells. Medical applications include treatment of blood disorders, spinal injuries and diabetes.
8The Agni-V missile is classified as:
Answer: B — Intercontinental Ballistic Missile (ICBM)
Agni-V is India's first Intercontinental Ballistic Missile (ICBM) with a range exceeding 5,000 km (some reports say 8,000 km). It can carry a nuclear warhead and brings most of Asia and parts of Europe within India's strike range. Developed by DRDO, it was successfully tested and inducted into service. India uses the "no first use" nuclear doctrine.
Agni-V is India's first Intercontinental Ballistic Missile (ICBM) with a range exceeding 5,000 km (some reports say 8,000 km). It can carry a nuclear warhead and brings most of Asia and parts of Europe within India's strike range. Developed by DRDO, it was successfully tested and inducted into service. India uses the "no first use" nuclear doctrine.
9Photovoltaic cells convert which energy into electricity?
Answer: C — Solar (light) energy
Photovoltaic (PV) cells convert solar light energy directly into electricity through the photovoltaic effect — when photons (light particles) knock electrons loose from atoms in a semiconductor material (usually silicon), generating an electric current. India has one of the world's largest solar power programmes under the National Solar Mission.
Photovoltaic (PV) cells convert solar light energy directly into electricity through the photovoltaic effect — when photons (light particles) knock electrons loose from atoms in a semiconductor material (usually silicon), generating an electric current. India has one of the world's largest solar power programmes under the National Solar Mission.
10The Human Genome Project was completed in:
Answer: B — 2003
The Human Genome Project (HGP) was an international scientific research project that sequenced and mapped all human genes (approximately 20,000-25,000 genes, 3 billion base pairs). Initiated in 1990, it was formally completed in April 2003. It has revolutionised medicine, enabling genetic testing, personalised medicine and understanding of genetic diseases.
The Human Genome Project (HGP) was an international scientific research project that sequenced and mapped all human genes (approximately 20,000-25,000 genes, 3 billion base pairs). Initiated in 1990, it was formally completed in April 2003. It has revolutionised medicine, enabling genetic testing, personalised medicine and understanding of genetic diseases.
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