Q1. Write in chronological order
(i) ‘Man’s landing on moon
(ii) Discovery of radio activity
(iii) First nuclear explosion
(iv) Launching of first satellite by India
(a) (iii), (ii), (iv), (i)
(b) (i), (ii), (iii), (iv)
(c) (iii), (i), (iv), (ii)
(d) (ii), (iii), (i), (iv)
Answer: (d) (ii), (iii), (i), (iv)
Explanation:
The correct chronological order is:
- Discovery of radioactivity (1896 by Henri Becquerel)
- First nuclear explosion (1945, USA)
- Man’s landing on moon (1969, Apollo 11)
- India’s first satellite launch (Aryabhata in 1975)
This sequence reflects the progression of major scientific and technological milestones.
Q2. Which of the following discoveries is/are associated with Einstein ?
(i) Theory of relativity
(ii) Quantum theory
(iii) Radio activity
(iv) Rocket propulsion
(a) (i) & (ii)
(b) (i), (ii) & (iii)
(c) (i), (ii) & (iv)
(d) (i) only
(UPSC Prelims 1984)
Answer: (d) (i) only
Explanation: Albert Einstein is most famously associated with the Theory of Relativity, which revolutionized physics. While he contributed to quantum theory, he did not discover it. Radioactivity and rocket propulsion were developed by other scientists, making (i) only the correct choice.
Q3. India has decided to acquire …. to match Pakistan’s F-16
(a) Jaguars
(b) MIG-29
(c) Mirage-2000
(d) Harpoon
(UPSC Prelims 1984)
Answer: (b) MIG-29
Explanation: To counter Pakistan’s acquisition of F-16 fighter jets, India opted for the MIG-29, a Soviet-origin multirole combat aircraft known for its agility, speed, and advanced avionics. This move was part of India’s strategy to maintain air superiority and regional balance.
Q4. The tape of the tape-recorder is coated with
(a) Copper sulphate
(b) Mica
(c) Ferromagnetic powder
(d) Zinc oxide
(UPSC Prelims 1984)
Answer: (c) Ferromagnetic powder
Explanation: Tape recorder tapes are coated with ferromagnetic powder, which allows for the magnetic storage of audio signals. These particles respond to electromagnetic fields, enabling recording and playback through magnetic heads.