61. If the angle between the radii of a circle is 110°, then the angle between the tangents at the ends of the radii is 90° 50° 70° 40° Answer: 70° 62. A point A is 5 cm away from the center of a circle and the length of the tangent from A is 4

41. If p is the perpendicular distance from the origin to the line whose intercepts on the axes are a and b, then p² = a² + b² p² = a² – b² 1/p² = 1/a² + 1/b² 1/p² = 1/a² – 1/b² Answer: 1/p² = 1/a² + 1/b² 42. The equation of the line

21. If logₓ256 = 8/5, then x = 64 16 32 8 Answer: 16 22. The direction cosines of the vector 3i – 4j + 5k are 3/5, -4/5, 1/5 3/5√2, -4/5√2, 1/√3 3/√2, -4/√2, 1/√2 None of these Answer: 3/5, -4/5, 1/5 23. lim(x→1) (1 + log x – x)/(1 – 2x + x²)

1. cos1° + cos2° + cos3° + … + cos180° = 0 1 2 -1 Answer: 0 2. The value of (tan70° – tan20°) / tan50° is 0 1 2 3 Answer: 1 3. If cos⁻¹x + cos⁻¹y + cos⁻¹z = 3π, then xy + yz + zx = 1 0 3 -3 Answer: 0

281. The allotrope of carbon that has a high melting point is Graphite Fullerene Coke Diamond Answer: Diamond 282. The compound that gives a smoky flame when burned is CH₄ C₂H₆ C₂H₂ C₂H₄ Answer: C₂H₂ 283. The process of adding hydrogen to an alkene in the presence of a nickel catalyst is called _______. Hydrogenation

261. The color of the Taj Mahal in Agra has changed due to _______. Sunlight Acid rain Lime Corrosion Answer: Acid rain 262. Antacids are used to remove _______. Body pain Acidity Alkalinity Headache Answer: Acidity 263. The chemical compound present in toothpaste is Alkaline – Ca₃(PO₄)₂ Acidic – Ca₃(PO₄)₂ Alkaline – Ca(HCO₃)₂ Salt –

241. The pH of milk of magnesia is _______. 11 10 11.5 10.5 Answer: 10.5 242. Venus’s atmosphere is composed of thick white and yellow clouds of _______. H₂SO₄ HCl HNO₃ H₂SO₃ Answer: H₂SO₄ 243. _______ acid is present in tomatoes. Oxalic Citric Tartaric Methanoic Answer: Tartaric 244. An aqueous solution of sodium chloride is

221. The gas evolved when manganese reacts with very dilute HNO₃ is _______. H₂ N₂ O₂ NO₂ Answer: NO₂ 222. The order of reactivity is _______. Al > Mg > Fe > Zn Mg > Al > Zn > Fe Al > Mg > Zn > Fe Mg > Al > Fe > Zn Answer:

201. Sulfuric acid is treated with _______. O₂ SO₂ H₂ SO₂ Answer: H₂ 202. Quick lime is _______. CaO CaCl₂ Ca(OH)₂ Ca(HCO₃)₂ Answer: CaO 203. Slaked lime slowly reacts with CO₂ in the air to form _______. Ca(HCO₃)₂ CaO Ca(OH)₂ CaCO₃ Answer: CaCO₃ 204. During respiration in cells, _______ combines with oxygen to produce CO₂