Science~12 min read
Physics, chemistry, biology
Motion, light, electricity, acids, metals, cells, diseases.
- v = u + at, s = ut + ½at², v² = u² + 2as. Speed is scalar; velocity is vector. Acceleration due to gravity g ≈ 9.8 m/s².
- Newton: 1st inertia, 2nd F=ma, 3rd action–reaction. Momentum p=mv; impulse = change in momentum.
- Light: i=r (reflection); refraction n = c/v = sin i / sin r. TIR when i > critical angle (optical fibre). Dispersion — prism; rainbow.
- Electricity: V=IR; series current same, parallel voltage same. Power P=VI=I²R. Earthing for safety.
- Acids donate H⁺; bases donate OH⁻; pH 7 neutral. Metals: electropositive, form basic oxides; non-metals acidic oxides.
- Cell: prokaryote no membrane-bound nucleus; mitochondria — ATP; chloroplast — photosynthesis. Blood: RBC (Hb), WBC, platelets, plasma.
- Diseases: communicable (TB — Mycobacterium; malaria — Plasmodium, Anopheles) vs non-communicable (diabetes, hypertension). Vaccines — active immunisation.
Video Lectures & Explanations
Curated educational video lectures explaining this topic for UPSC EPFO