CBSE ADDA

Time: 3-3and1/2 hr _ Max mark: 100 [includes 10 marks based on Open Text Theme] Test held in School: Sadhana Devi Vidyapith, Samastipur - Punjabi Colony [By JSunil] 1 mark 1. As per the law of definite proportional carbon and oxygen combine in ratio 3: 8. Compute the mass of oxygen gas that would be required to react completely with 6 gm carbon. 2. A pore bearing organism like creature “A” belong to a phylum “B” of kingdom Animalia. 3. In which reason is soil erosion very difficult to revert. 2 marks 4. Explain, What is Organ specific manifestation? 5. A man drops a stone of mass 2 kg room the top of a building of height 15m when it reaches the ground, find its kinetic energy. 6. When an object is immersed in the fluid name the two forces acting on it. 3 marks 7. (a) The mass number of an element is 18. It contains 7 electrons. What is the number of proton? and neutron in it. (b) State the problem of atomic structure which was solved after the discovery

Q. Find the gram molecular mass of water (H2O) Calculation: 2(H) = 2 x 1 = 2 . 1(O) = 1 x 16 = 16 ∴ Gram molecular mass of H2O= 18g Mole is defined as the amount of substance that contains as many specified elementary particles as the number of atoms in 12g of carbon-12 isotope. One mole is also defined as the amount of substance which contains Avogadro number (6.023 x 10^23) of particles. For eg. one mole of oxygen atoms represents 6.023 x 10^23 atoms of oxygen and 5 moles of oxygen atoms contain 5 x 6 . 0 2 3 x 10 ^23 a t oms of oxygen . Q. Calculate the number of aluminium ions present in 0.051 g of aluminium oxide. [Hint : The mass of an ion is same as that of an atom of the same element. Sol: 1 mole of Al2O3 contains aluminium ions = 2 × 6.022 × 10^23 = 12.044 × 10^23 Now, 102 g of Al2O3 has number of aluminium ions = 12.044 × 10^23 0.051 g of Al2O3 has number of aluminium ions = (12.044 ×1023 × 0.051)/102= 6.022 × 10^20 ions Q. How many atoms of oxygen are present i

Q1 The first three terms of an AP respectively are  3y – 1, 3y + 5 and 5y + 1. Then y equals: (A) –3 (B) 4 (C) 5 (D) 2 Solution: (C) 5 Q2 In Fig. 1, QR is a common tangent to the given circles, touching externally at the point T. The tangent at T meets QR at P. If PT = 3.8 cm, then the length of QR (in cm) is : (A) 3.8 (B) 7.6 (C) 5.7 (D) 1.9 Solution: (B) 7.6 Q3 In Fig. 2, PQ and PR are two tangents to a circle with centre O. If ∠QPR = 46°, then ∠QOR equals: (A) 67° (B) 134° (C) 44° (D) 46° Solution: (B) 134° Q4. A ladder makes an angle of 60° with the ground when placed against a wall. If the foot of the ladder is 2 m away from the wall, then the length of the ladder (in metres) is: (A) 43 (B) 43 (C) 22 (D) 4 Solution: (D) 4 Q5 If two different dice are rolled together, the probability of getting an even number on both dice, is: (A) 136 (B) 12 (C) 16 (D) 14 Solution: (D) 14 Q6 A number is selec

SECTION A All questions are similar in 30/2 set                             SECTION B All questions are similar in 30/2 set except Q.No. 14 14. Find the value of p so that p x (x-3)+9 = 0 has equal roots. SECTION C All questions are similar in 30/2 set except Q. No. 20,22,23,24 20. Construct a triangle with side 5 cm, 5.5 cm and 6.5 cm . Now construct another triangle, whose sides are 3/5 times the corresponding sides of given triangle. 22. The sum of first seven term of AP is 182. If 4th and 17th term are in ratio 1: 5 . Find AP 23.From the top of 60m high building , the angle of depression of the top and bottom of a tower are 45 deg. and 60 deg. respectively. Find the height of tower. 24.Find a point p on y axis which is equidistant from points A(4,8)and B(-6,6) SECTION D All questions are similar in 30/2 set except Q.No.31, 32 and 34 31. (x – 4) / (x – 5 )/ (x – 6) / (x – 7 ) = 10/3 32. Five cards – the ten, jack ,queen king and ace of diamonds are are well