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UPPCS Physics Gap Sheet: Devices, Inventions and Discoveries.
UPPCS has asked 16 of these. 10 have not been asked yet. Lock the first list, then read the second: it holds what UPPCS has not used yet.
First, the concept
A discovery identifies a natural phenomenon; an invention creates a device. X-rays were discovered, while a barometer was invented. Name the specific contribution rather than crediting one person with every later version.
Many technologies developed in stages. Separate an early working device from a later improvement. The purpose and physical principle make inventor-device pairs easier to remember.
✅ Already asked (16)
Measuring and optical devices
- Mercury thermometer — Fahrenheit · Daniel Gabriel Fahrenheit developed the mercury-in-glass thermometer in 1714.
Electrical devices
- Daniell cell — Daniell · John Frederic Daniell developed this electrochemical cell in 1836.
- Faraday disk generator · Faraday built an early electromagnetic generator in 1831.
- Steam-engine improvement — Watt · James Watt's separate condenser greatly reduced wasted heat.
- Commercial incandescent lighting — Edison · Edison developed a practical incandescent lighting system; earlier lamps already existed.
- Transistor — Bell Labs team · Bardeen, Brattain and Shockley received the 1956 Physics Nobel for semiconductor research and the transistor effect.
- Integrated circuit — Kilby and Noyce · Jack Kilby and Robert Noyce independently contributed to early integrated circuits.
Discoveries of physical phenomena
- X-rays — Roentgen · Wilhelm Conrad Roentgen discovered X-rays in 1895.
- Radioactivity — Becquerel · Henri Becquerel discovered spontaneous radioactivity in uranium salts in 1896.
- Electron — J. J. Thomson · Cathode-ray experiments led to its discovery in 1897.
- Neutron — Chadwick · James Chadwick discovered the neutron in 1932.
- Atomic nucleus — Rutherford · Alpha-particle scattering revealed a small, dense, positively charged nucleus.
- Raman effect — C. V. Raman · Inelastic scattering changes the frequency of a small fraction of scattered light.
Further landmark contributions
- First working laser — Maiman · Theodore Maiman demonstrated a ruby laser in 1960.
- Electromagnetic induction — Faraday · Faraday demonstrated induction in 1831; Joseph Henry also discovered it independently.
- Neutrino proposal — Pauli · Wolfgang Pauli proposed a neutral particle in 1930 to explain beta-decay energy accounting.
❌ Not asked yet (10)
Items marked 'asked in other exams' have come in UPSC or other state exams, not yet in UPPCS.
🔒 10 items not asked yet
Measuring and optical devices: 5 · Electrical devices: 2 · Further landmark contributions: 3
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⚠️ Watt improved the steam engine; he did not invent the first steam engine. Roentgen discovered X-rays rather than all later X-ray machines.
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