Part I — Multiple Choice Questions 9 × 1 = 9
Choose the correct answer. (Answer all questions.)
1.If tangents PA and PB from a point P to a circle with centre O are inclined to each other at angle of $80^\circ$A. $50^\circ$B. $60^\circ$C. $70^\circ$D. $80^\circ$[1]
2.A tangent PQ at a point P of a circle of radius 5 cm meets a line through the centre O at a point Q so that OQ = 12 cm. Length PQ is :A. 12 cmB. 13 cmC. 8.5 cmD. $\sqrt{119}$ cm[1]
3.Choose the correct option and justify your choice : (i) $\dfrac{2\tan30^\circ}{1+\tan^230^\circ}$A. As listed in the question.B. As listed in the question.C. As listed in the question.D. As listed in the question.[1]
4.Tick the correct answer in the following : Area of a sector of angle $p$A. $\dfrac{p}{180}\times2\pi R$B. $\dfrac{p}{180}\times\pi R^2$C. $\dfrac{p}{360}\times\pi R^2$D. $\dfrac{p}{720}\times2\pi R^2$[1]
5.In Fig. 10.11, if TP and TQ are the two tangents to a circle with centre O so that $\angle POQ = 110^\circ$A. $60^\circ$B. $70^\circ$C. $80^\circ$D. $90^\circ$[1]
6.Which of the following cannot be the probability of an event?A. $\dfrac{2}{3}$B. $-1.5$C. $15\%$D. $0.7$[1]
7.From a point Q, the length of the tangent to a circle is 24 cm and the distance of Q from the centre is 25 cm. The radius of the circle isA. 7 cmB. 12 cmC. 15 cmD. 24.5 cm[1]
8.Choose the correct option. Justify your choice. (i) $9\sec^2 A - 9\tan^2 A$A. As listed in the question.B. As listed in the question.C. As listed in the question.D. As listed in the question.[1]
9.Choose the correct choice in the following and justify : (i) 30th term of the AP: 10, 7, 4, . . . , is (A) 97 (B) 77 (C) -77 (D) - 87 (ii) 11th term of the AP: $-3, -\dfrac{1}{2}, 2, . . .$A. As listed in the question.B. As listed in the question.C. As listed in the question.D. As listed in the question.[1]
Part II — Short Answer Questions 18 × 2 = 36
Answer briefly. (Answer all questions.)
10.Sides AB and BC and median AD of a triangle ABC are respectively proportional to sides PQ and QR and median PM of $\triangle PQR$[2]
11.Solve the following pair of linear equations by the substitution method. (i) $x + y = 14$[2]
12.A student noted the number of cars passing through a spot on a road for 100 periods each of 3 minutes and summarised it in the table given below. Find the mode of the data : Number of cars: 0 - 10, 10 - 20, 20 - 30, 30 - 40, 40 - 50, 50 - 60, 60 - 70, 70 - 80 Frequency: 7, 14, 13, 12, 20, 11, 15, 8[2]
13.The first term of an AP is 5, the last term is 45 and the sum is 400. Find the number of terms and the common difference.[2]
14.Solve the problems given in Example 1.[2]
15.Solve the following pair of linear equations by the elimination method and the substitution method: (i) $x + y = 5$[2]
16.The diagonals of a quadrilateral ABCD intersect each other at the point O such that $\dfrac{AO}{BO} = \dfrac{CO}{DO}$[2]
17.A bag contains lemon flavoured candies only. Malini takes out one candy without looking into the bag. What is the probability that she takes out (i) an orange flavoured candy? (ii) a lemon flavoured candy?[2]
18.The table below shows the daily expenditure on food of 25 households in a locality. Daily expenditure (in ₹): 100 - 150, 150 - 200, 200 - 250, 250 - 300, 300 - 350 Number of households: 4, 5, 12, 2, 2 Find the mean daily expenditure on food by a suitable method.[2]
19.If $P(E) = 0.05$[2]
20.A gulab jamun, contains sugar syrup up to about 30% of its volume. Find approximately how much syrup would be found in 45 gulab jamuns, each shaped like a cylinder with two hemispherical ends with length 5 cm and diameter 2.8 cm (see Fig. 12.15).[2]
21.To find out the concentration of $SO_2$[2]
22.If the sum of first 7 terms of an AP is 49 and that of 17 terms is 289, find the sum of first n terms.[2]
23.Find the coordinates of a point A, where AB is the diameter of a circle whose centre is (2, - 3) and B is (1, 4).[2]
24.Which of the following are APs ? If they form an AP, find the common difference d and write three more terms. (i) 2, 4, 8, 16, . . . (ii) $2, \dfrac{5}{2}, 3, \dfrac{7}{2}, . . .$[2]
25.Suppose you drop a die at random on the rectangular region shown in Fig. 14.6. What is the probability that it will land inside the circle with diameter 1 m?[2]
26.For the following APs, write the first term and the common difference: (i) 3, 1, - 1, - 3, . . . (ii) - 5, - 1, 3, 7, . . . (iii) $\dfrac{1}{3}, \dfrac{5}{3}, \dfrac{9}{3}, \dfrac{13}{3}, . . .$[2]
27.A spiral is made up of successive semicircles, with centres alternately at A and B, starting with centre at A, of radii 0.5 cm, 1.0 cm, 1.5 cm, 2.0 cm, . . . as shown in Fig. 5.4. What is the total length of such a spiral made up of thirteen consecutive semicircles? (Take $\pi = \dfrac{22}{7}$[2]