NDA/NA National Defence Academy/Naval Academy Practice Set 1
Instructions (i) This practice set contains 270 questions in all comprising Paper 1 (Mathematics 120 questions) and Paper 2 (Part-A English 50 questions) and (Part-B General Ability 100 questions) (ii) Candidate/Student should attempt all questions. (iii) Each question is followed by four alternative suggested answers or completions. In each case, you are required to select the one that correct the answer. (iv) For each questions for which a wrong answer has been given by the candidate, only third (0.33) of the marks assigned to the questions will be deducted as penalty.
S. No. Contents No. of Questions Max Marks Time Allotted Paper 1 Mathematics 120 300 2 : 30 hrs Paper 2 English and General Ability 150 600 2 : 30 hrs
Paper 1 Mathematics
1. The number of solutions to the equation z2 + z = 0 6. The degree of the differential equation is dz dz 4z= y + sin is (a) 1 (b) 2 (c) 3 (d) 4 dy dy 2. If|z2−1 | = | z 2 | + 1, then z lies on a (a) 0 (a) real axis (b) imaginary axis (b) 1 (c) non-real axis (d) None of these (c) 2 3. If three complex number are in arithmetic (d) Cannot be determined progression, then they lie on in complex plane. dy 3x− 4 y − 2 7. The solution of the equation = is (a) circle (b) parabola dx 3x− 4 y − 3 (c) straight line (d) None of these (a) (x− y )2 + C = log(3 x − 4 y + 1 ) 4. What is the number of solutions of the equation (b) x− y + C =log(3 x − 4 y + 4 ) 2 − + = x5| x | 6 0? (c) x− y + C =log(3 x − 4 y − 3 ) (a) 2 (b) 0 (c) 1 (d) 4 (d) x− y + C =log(3 x − 4 y + 1 ) dx 5. The differential equation y =y − 1, y( )0= 1has 8. The orthogonal trajectory of the family of dy parabolas x2 =4 µ y, µ being parameter is (a) unique solutions (b) two solutions (a) x2+ y 2 = C (b) 2x2+ y 2 = C (c) infinite number of solutions (d) no solutions (c) x2+2 y 2 = C (d) x2−2 y 2 = C 2 Practice Set 1 10 Practice Sets for NDA/NA Exam
2− 3 19. If roots of the equation ax2 + bx + c = 0 are in the 9. The inverse matrix of is − λ 4 2 ratio λ :1, then the value of is 1 2 3 1 2 4 ()λ + 1 2 (a) − (b) − bc ca 8 4 2 8 3 2 (a) (b) a b 1 2 3 1 2 4 ca bc (c) (d) (c) (d) 8 4 2 8 3 2 b2 a2 10. If A is a square matrix, then()AA+ T is 20. If x=3 + i, then the value of the expression (a) null matrix (b) an identity matrix x3−3 x 2 − 8 x + 15 is (c) a symmetric matrix (d) a skew-symmetric matrix (a) −15 (b) −1 11. A matrix which is symmetric and skew-symmetric (c) 8 (d) 3 21. 2 − + = is If log10 (x6 x 45 ) 2, then the value of x (a) orthogonal matrix (b) idempotent matrix (a) 6, 9 (b) 10, 5 (c) null matrix (d) None of these (c) 9, 5 (d) 11, − 5 12. 64 What is the number of digits in( )20 ? 22. If ABC, and are three sets, then ABC×() ∪ is = (if log10 2 0301. ) equal to (a) 81 (b) 82 (c) 83 (d) 84 (a) ()()ABAC× ∩ × (b) ()()ABAC∩ × ∩ 13. Which one of the following statement is correct? (c) ()()ABAC× ∪ × (d) None of these The numbers log6 7, log42 7, log294 7 in 23. The relation ‘less than’ in the set of natural number (a) AP (b) HP is (c) GP (d) None of these (a) symmetric (b) transitive (c) reflexive (d) equivalence relation 2 − 1+x − 1 14. If y = tan 1 , then 24. If R′ is the set of all straight lines in a plane and the x relation R is defined by aRb if a⊥ b for a, b∈ R ′, then dy = dy = 1 (a) 1 (b) (a) R is reflexive (b) R is symmetric dx = dx = 2 x 0 x 0 (c) R is anti-symmetric (d) None of these dy = (c) 0 (d) None of these 25. If the AM and HM of two numbers are 25 and 4, dx = x 0 then their GM is 2 (a) 10 (b) 9 −1 2 d y 15. If x= sin ( t ) and y=log (1 − t ), then is (c) 16 (d) None of these dx 2 cosx− sin x equal to 26. lim is equal to π π 2 − 2 x → − (a) (b) 4 x 1−t 2 1−t 2 4 1 1 (c) (d) None of these (a) −1 (b) − (c) 2 (d) − 2 1−t 2 2 π /2 16. d x+ a 27. The value of ∫ log tan x dx ()a x is equal to 0 dx π x a π − − − a x (a) loge 2 (b) loge 2 (a) x()() ax1+ a x a 1 (b) + 2 loga log x (c) 0 (d) e x a (c) alog a+ x (log x ) (d) None of these dx 28. ∫ is equal to d 2 2+ 2 2 17. (cosx° ) is equal to acos x b sin x dx −1 a + 1 −1 b + π (a) tan tan x C (b) tan cot x C (a) −sin x ° (b) −sin x ° b ab a 180 1 − b 180 (c) tan1 tan x + C (d) None of these (c) −sin x ° (d) None of these π ab a 18. 1 3 2 If the sum of ‘n’ terms of a series is a quadratic 29. If A = and AKAI− −5 = 0, then K is equal expression in ‘n’, then the series is 3 4 (a) GP (b) HP to (c) AP (d) None of these (a) 5 (b) 3 (c) 7 (d) 4 10 Practice Sets for NDA/NA Exam Practice Set 1 3
30. The value of the determinant x 1 3 −a2 − ab ac 40. If the determinant 0 0 1 = 0, then x is equal to 2 ba− b bc is 1x 4 − 2 − − ac bc c (a) 2or 2 (b) 3 or 3 (c) 1 or −1 (d) 3 or 4 2 2 2 (a) abc (b) a b c 41. The class marks of a distribution are 6, 10, 14, 18, (c) 1 (d) 0 22, 26, 30, then the class size is 31. Solution of the differential equation (a) 4 (b) 2 sec2x tan y dx+ sec 2 y tan x dy = C is (c) 5 (d) 7 42. (a) tanx+ tan y = C (b) tanx tan y= C A graph representing cummulative frequency is (c) tanx− tan y = C (d) tanx sec y= C termed as (a) ogive (b) bar charts 32. The solution of the differential equation (c) pie charts (d) histogram dy y + = x n is 43. A committee of 3 is to be chosen from a group dx x consisting of 4 men and 5 women. If the selection y (a) =C (b) y+ x = C is made at random, then the probability that two of x + the members of committee are men, is given by x n 2 x n (c) yx = + C (d) y = + C (a) 3/14 (b) 5/14 n + 2 n + 2 (c) 1/21 (d) 8/21 2 33. The necessary condition for a maximum or 44. − x2 dx The value of the integral ∫− 1| | minimum of a function f() x is 2 df dn f (a) 2 (b) 4 (a) ≠ 0 (b) = + ve (c) 0 (d) 1 dx dx 2 45. d2 f df The value of the scalar triple product (c) = − ve (d) = 0 []a b+ c a +b + c is dx 2 dx (a) 0 (b) 1 2 2 π /2 sinx− cos x (c) |a ||b || c | (d) None of these 34. The value of ∫ dx is 0 sin3x+ cos 3 x 46. The area of the triangle with vertices (a) 0 (b) 1 i+ j , i+ k , j+ k is 1 1 (c) (d) 3 2 3 (a) 3 (b) 2 35. 2− + 2 + − + = 1 2 The conic 17x 12 xy 8 y 46 x 28 y 170 (c) (d) represents 3 3 (a) circle (b) ellipse 47. Distance between the planes (c) parabola (d) hyperbola 2x− 2 y + z + 1 = 0 and 4x− 4 y + 2 z + 3 = 0 is 36. The expression (a) 1/2 (b) 1/3 (c) 1/6 (d) 0 cos(ABABABAB− )cos( + ) − sin( − )sin( + ) 48. The maximum value of sinx+ cos x is is equal to (a) 1 (b) − 2 (c) 2 (d) 1+ 2 (a) 2sinAB cos (b) sin 2A (c) cos 2A (d) 2 cosAB sin 49. The value of[,,]a− b b − c c − a 1 1 (a) 0 (b) 1 37. If tan A = and tan B = , then what is the value (c) 2 (d) None of these 2 3 of tan (2AB+ )? 50. The number of vectors of unit length perpendicular (a) 1 (b) 2 (c) 3 (d) 4 to the vector a = (,,)1 1 0 and b = (,,)0 1 1 is 38. ω (a) one (b) two If is a complex cube root of unity, then the value (c) three (d) None of these of ω99+ ω 100 + ω 101 is 51. A tower of height 15 m stands vertically on the (a) 1 (b) −1 ground. From a point on the ground the angle of (c) 3 (d) 0 elevation of the top of the tower is found to be 30°. 39. The number 1753 in binary notation is What is the distance of the point from the foot of the tower? (a) ()11011011101 2 (b) ()11011111001 2 (a) 15 3 m (b) 10 3 m (c) 5 3 m (d) 30 m (c) ()11011011001 2 (d) None of these 4 Practice Set 1 10 Practice Sets for NDA/NA Exam
52. A husband and wife appear in an interview for two 63. If x=1 + a + a2 +… ∞,()a < 1, vacancies at the same post. The probability of = + +2 +… ∞ < 1 y1 b b,() b 1, husband selection is and that of wife selection is 5 then the value of1 +ab + a2 b 2 + … ∞ is 1 xy xy xy xy . What is the probability that only one of them will (a) (b) (c) (d) 3 x+ y −1 x+ y + 1 x− y −1 x− y + 1 be selected. 1 2 64. The sum of n terms of an AP be 3n2 + 5, then the (a) (b) 5 5 number of terms which is equal to 159? 3 4 (c) (d) (a) 13 (b) 21 5 5 (c) 27 (d) None of these 53. The points(,)a b (0, 0)(,)−a − b,(,)ab b2 are 65. The purpose of Tabulation is (a) vertices of parallelogram (b) vertices of rectangle (a) to simplify presentation only (c) vertices of square (d) collinear (b) to simplify presentation as well as facilitate comparison (c) to facilitate comparison only x 2 y2 54. The eccentricity of the ellipse + = 1is (d) None of the above 25 9 66. The probability of having a king and a queen when 2 4 (a) (b) the two cards are drawn at random from a pack of 5 5 3 52 cards is (c) (d) None of these 16 8 5 (a) (b) 663 663 55. The number of the diagonal of octagon is 4 (c) (d) None of these (a) 48 (b) 40 663 (c) 28 (d) 20 67. ∫ elog cos x dx is equal to 56. If|a |= | b |and|a× b | = 1, then the value of|a+ b | is equal to (a) sin x+ C (b) −sin x + C cos x (a) 1 (b) 3 (c) e+ C (d) None of these 3 (c) 2 (d) 68. ∫ ax dx is equal to 2 a x 57. If b is a non-zero vector of modulus b and α is a (a) + C (b) ax log a+ C log a non-zero scalar, then k b is a unit vector. If the + a x 1 value of b is equal to (c) + C (d) None of these (a) k (b) |k | x + 1 1 1 (c) (d) 69. sin3 x cos x dx is equal to |k | k ∫ 1 4 + 1 4 + 58. If a and b are two unit vectors inclined at an angle (a) cos x C (b) sin x C π 4 4 , then the value of|a+ b |is (c) sin4 x+ C (d) cos4 x+ C 3 (a) greater than 1 (b) less than 1 70. The velocity v of a particle moving in a straight line (c) equal to 1 (d) equal to 0 is given by the following v2=2 s 2 + 4 s + 5, its 59. The base of decimal number system is acceleration at s = 5 is (a) 8 (b) 2 (a) 10 (b) 12 (c) 10 (d) e (c) 14 (d) 75 60. A unit vector perpendicular to the two vectors 71. If ω is a cube root of unity, then the value of i+2 j − k and 2 i+3 j + k is equal to ()()1+ 3ω + 3 ω2 10 + 3 + ω + 3 ω 2 10 +()3 + 3ω + 3 ω2 10 (a) 35(5i−3 j − k ) (b) 35(5i− 3 j − k) is 1 − − (a) 0 (b) 1 (c) ()5i 3 j k (d) None of these 2 35 (c) 1+ ω (d) 1+ ω 61. π π Convert(55.625)10 into binary number 72. = + ⋅ ⋅ … ∞ ⋅ ⋅ If zk cos i sin , then z1 z 2 z 3 is (a) ()110 111 101 2 (b) ()101111 111 2 2k 2 k (c) ()111001⋅ 101 (d) None of these 2 equal to 62. Convert()1111 to its decimal equivalent 1 1 2 (a) −1 (b) 1 (c) − (d) (a) 13 (b) 14 (c) 15 (d) 16 2 2 10 Practice Sets for NDA/NA Exam Practice Set 1 5
73. Set of natural number of elements is not closed 82. The above curve shows the graph of ax under (a) for addition operation (b) for subtraction operation which one of the following condition (c) for multiplication operation(d) None of these y 74. The inverse of matrix A exists, if A is a square matrix and (a) A = 0 (b) A ≠ 0 (c) |A | = 0 (d) |A | ≠ 0 75. If sin2AB= λ sin 2 , then what is the value of tan (AB+ ) ? x tan (AB− ) (a) a ≥1 (b) a >1 λ −1 λ + 1 λ2 −1 λ −1 (c) 0