21. Which is the hardest mnterinl ever known in the universe? (A) Platinum (C) Diamond (B) Graphite (D) Marble
22. Which instrument regulates the resistance or current in a circuit? (A) Volta cell (B) Rheostat (D) Sonometre (C) Generator 23. The scientist who formulated the "Germ theory of disease" in (A) Louis Pasteur (C) Hugo Devries (B) lamarck (D) Griger Mendel 24. In which atmopheric level ozone gas is seen? (A) Mesosphere (C) Stratoephere (B) Lithosphere (D) lonosphere
25. Which in the relay centre in our brain? (A) Pituitary gland (C) Spinal cord (B) Thalamus (D) Meninges 26. Methane ga is invented by the scientist: (A) Alexandro Volta (C) John Dalton (B) (D) Alexander Fleming Thoman Alwa Edison
27. Which of the following units in usually used to denote the intensity of pollution? (A) Milligram (C) Parts per million (B) Nanograms (D) Kilogram 28. Nitrogen fixing b ctenn lives in the root tumourn of pea-plants is called : (B) Rhizobium (D) Streptococcus (A) Rhizome (C) E.coli 29. Which of the following chemicals is used in ire extinguisher ? (A) Sodium bicarbonate (C) Potassium bicarbonate (B) Sodium nitrate (D) Sodium chloride 30. Which phenomenon of light is behind the rainbow? (A) Diffraction (C) Reflection (B) Scattering (D) Radiation
MSc physics graduate.3 year experience in PSC field.HARISREE PSC Telegram Channel. LDC Thrissur Rank 707.