SilverZone iOS Sample Paper Class 12

International Olympiad of Science - iOS’ 22 CLASS 12th SAMPLE QUESTIONS The Actual Question Paper Contains 40 Questions. The Duration of the Test Paper is 50 Minutes. 1. A voltmeter of resistance 400 Ω is used to measure the 6. The relative order of acidity of alcohols in comparison emf of a cell of internal resistance 2 Ω. The percentage to H2O and HC CH is error in reading of the voltmeter is very nearly equal (A) H2O > ROH > HC CH to (B) H2O > HC CH > ROH (A) 0.5% (B) 0.8% (C) ROH > H2O > HC CH (C) 1% (D) 1.25% (D) ROH > HCOOH > H2O 2. Choose the wrong statements from the following. The x–4 2x 2x force experienced by a charged particle moving with a 7. If 2x x–4 2x = (A + Bx)(x–A)2, then the velocity v in an electric field E is zero if (A) v = 0 2x 2x x–4 (B) v is parallel to B ordered pair (A, B) is equal to (C) v is antiparallel to B (A) (–4, –5) (B) (–4, 3) (D) All of these (C) (–4, 5) (D) (4, 5) 3. In the Bohr model of the hydrogen atom, the ratio of 8. If the system of linear equations the kinetic energy to the total energy of the electron x + ky + 3z = 0 in a quantum state n is 3x + ky – 2z = 0 (A) –1 (B) + 1 2x + 4y – 3z = 0 1 1 xz (C) n (D) n2 has a non-zero solution (x, y, z) then 2 is equal to (A) –10 (B) 10 y 4. The vapour pressure of pure benzene and toluene are (C) –30 (D) 30 160 Torr and 60 Torr, respectively. The mole fraction 9. Inhibition of secretion of which of the following of benzene in vapour phase in contact with equimolar hormones is necessary for disintegration of corpus solution of benzene and toluene would be luteum? (A) 0.24 (B) 0.56 (A) Progesterone (B) LH (C) 0.73 (D) 0.11 (C) LTH (D) FSH 5. Which of the following ions is most effective in the 10. HIV selectively infects and kills coagulation of an arsenious sulphide sol? (A) B cells (B) Antibodies (A) K+ (B) Mg2+ (C) T-helper cells (D) T-cytotoxic cells (C) Al3+ (D) Ca2+ ANSWERS 1. (A) 2. (D) 3. (A) 4. (C) 5. (C) 6. (A) 7. (C) 8. (B) 9. (A) 10. (C) 18