CBSE ADDA

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

Series HRS Code-30/2 Summative Assessment –II Subject Mathematics class 10 CBSE Board 2014 SECTION-A 1. The probability that a number selected at random from the number 1,2,3,…..15. is a multiple of 4 is (A)4/15 (B) 2/15 (C)1/5 (D)1/3 Ans: 1/5 2. The angle of depression of car parked on the road from the top of a 150m high tower is 300 . The distance of the car from the tower in m meter is (A)50Ö3 (B)150Ö3 (C) 50Ö2 (D)75 Ans: (B)150Ö3 3. Two circle touches externally at P . AB is common tangent to the circle touching them at A and B . The value of <APB is (A)300 (B)450 (C)600 (D) 900 Ans: (B)450 4. If k,2k -1 and 2k + 1 are three consecutive term of AP then value of k is (A)2 (B)3 (C)-3 (D)5 Ans: (B)3 5. A chord of a circle of

1 marks 1. Write the symbols of the following elements. (a) Iron (b) Silver 2. State the phylum to which antedon (feather star) and asterias (Starfish) belong. 3. Mention two factors that influence the pattern of winds. 2 marks 4. Distinguish between Bryophyta and Thallophyta stating two examples of each. 5. List the causative organisms for the following diseases. (i) Kala-azar (ii) Sleeping sickness (iii) Acne (iv) AIDS 6. The volume of 50g of a substance is 20cm3. If the density of water is 1 g/cm3, will the substance float or sink in water ? Justify your answer. 7. What is the work done by the force of gravity in the following cases ? (a) Satellite moving around the earth in a circular orbit of radius 35000 km. (b) A stone of mass 250 g is thrown up through a height of 2.5 m. 3 marks 8. Define formula unit mass ? How is it calculated. ? Write the formula unit mass of (NH4)2 SO4 . (Given atomic mass : N = 14 u, H= 1 u, S = 32 u, O= 16 u). 9. (a) If

TIME : 3 hours           Maximum Marks : 90 Instructions Q. No. 1 to 10 are MCQs ( 1mark for each question) Q. No. 11 to 23 are short answer questions write in 60-80 words ( 3 marks for each question) Q. No. 24 to 30 are long are questions write in 100-125 words ( 5 marks for each question) Q. No. 31-1 and 31-2 are map questions. Please  attach the map inside the answer book  Q.1     When were the first written ‘Laws  of Cricket’ drawn?           (a) 1774        (b) 1775        (c)1776         (d)1780         or           Radical changes in women clothing were enabled by: (a)   New times (b)Women’s movement       (c)World  war (d)Industrial revolution Q2      When did Gandhiji adopt the short dhoti ,a form of dress and wore until his death ? (a)   1920 (b)1923         (c)1922         (d)1921 Q3      Why do trees grow faster in summer?           (a)Due to high temperature           (b)Due to longer duration of sunlight           (c)Due to low temperatur

Class VII Hots Science Questions Chapter : Transportation , Respiration , Excretion , Reproduction and Forest a natural wealth