Docstoc

maths

Document Sample
maths Powered By Docstoc
					       MATHEMATICS - 2007
                      (PRELIMINARY)


Time Allowed: 2 hours                      Maximum Marks: 300
1. Let X = {n : n is a positive integer, n:C:; 50}. If A = {n E
      X : n is even} and
      B = {n EX: n is a multiple of 7}, then what is the number of
      elements in the smallest subset of X containing both A and B ?
       (a) 28                         (b) 29
       (c) 32                         (d) 35
2. Let A = {t EN: 12 and t are relatively prime} and B = {t EN: t :c:;
       24}. What is the number of elements in A n B?
       (a) 10                         (b) 8
       ~7                             (~ 4
3. Let z = cos (n/8) + i sin (n/8) and A = {zn : n EN}. Which one of
       the following is correct?
       (a) A is not a finite set
       (b) A contains 12 non-real complex numbers
       (c) The number of elements in A is 16
       (d) A contains no integers
4. Which one of the following is correct?
       The equation x 3 - 266 x2 - (266)2 x + (266)3 = 0
       (a) has no multiple roots (b) has exactly one real root (c) has no
       non-real roots (d) has no integral roots
5. What is the sum of the roots of the equation
       {(x - 2)2 + 9} {(x - 3)2 + 4} = 0
       (a) 5                          (b) 10
       (c) 13                         (d) 18
6.    Let m be a positive integer, m ~ 2. If ai' a2' ........, am are the
      roots of the equation xm - 1 = 0, then what is the equation
      whose roots are
      131 = a2 + a3 + ........ + am - (m - 1) al
      132 =   al + a3 +...... + am - (m - 1) a2

      I3j=al + ............ +ai-I +aj+1 +...+am-(m-l)aj


      13m =   al + ......... + am-I - (m - 1) am ?
      (a) xm + mm = 0                 (b) xm - (-m)m = 0
      (c) xm + (m-l)m = 0             (d) xm - (m- I)m = 0
7.    If a, 13, yare the roots of the equation x3 - px2 + qx - r = 0,
      then what is the value of L a2/3 ?
      (a) pq + 3r                     (b) pq + r
      (c) pq - 3r                     (d) q2/r
8.    Let G be an infinite cyclic group and H is its subgroup. Which
      one of the following is correct?
      (a) H is not necessarily cyclic
      (b) H is finite
      (c) H is infinite
      (d) H is not necessarily abelian
9.    Let G * {e} be a group with no subgroup other than {e} and G.
      Then which one of the following is correct?
      (a) G is an infinite cyclic group
      (b) G is a finite cyclic group
      (c) G is an abelian non-cyclic group
      (d) G is neither abelian nor cyclic
10.
      Which one of the following groups is cyclic?
      (a) Z12 x Z9                    (b) ZIO x Z85
      (c) Z4 x Z25 x Z6               (d) Z22 x Z21 x Z65
11.   Which one of the following is a group?
      (a) (N, *), where a * b = a for all a, b e N
      (b) (Z, *), where a * b = a - b for all a, b e Z
      (c) (Q, *), where a * b = ab/2 for all a, b E; Q
      (d) (R, *), where a * b = a + b + 1 for all a, b e R Consider the
12.   group (R * x R, G), where R * = R '" to} and (a, b) G (c, d) = (ac,
      be + d). What are the identity element and the inverse of (a, b)
      respectively?
      (a) (1, 0) and (a-I, ba-I)
      (b) (0, 1) and (a-I, ba-I)
      (c) (0, I) and (a-I, - ba-I)
      (d) (1, 0) and (a-I, -ba-I)
13.   Which' one of the following statements is correct?
      (a) Abelian groups may have non-abelian subgroups (b)
      Non-abelian groups may have abelian subgroups (c) Cyclic
      groups may have non-cyclic subgroups
      (d) Non-cyclic groups cannot have cyclic subgroups Let a = (1
14.   3 5 7 II) (2 4 6) E SII' What is the smallest positive integer n
      such that an = a37 ?
      (a) 3                           (b) 5
      (c) 7                           (d) 11
15.       Let (R, +) be an abelian group. If multiplication '.' is defined on
          R by setting a . b = 0 for all a, b E R, then which one of the
          following statements is correct?
          (a) (R, +, .) is not a ring
          (b) (R, +, .) is a ring, but not commutative
          (c) (R, +, .) is a commutative ring, but has no unity (d) (R, +, .)
          is a field
16.       Consider the following assertions:
      .    1. The characteristic of the ring (Z, +, .) is zero.
          2. For every composite number n, Z n' the ring of
          residue classes modulo n, is a field.
      3. Z 5' the ring of residue classes modulo 5, is an
          integral domain.
      4. The ring of all complex numbers is a field.
      Which of the above assertions are correct?
      (a) 1, 3 and 4                  (b) 1, 2 and 3
      (c) 1, 2 and 4                  (d) 2, 3 and 4
17.   Let F be a finite field with n elements. What is the possible
      value ofn ?                            .
      (a) I                           (b) 36
      (c) 37                          (d) 125
18.   If R is a fmite integral domain with n elements, then what is
      the number of invertible elements under multiplication in R ?
      (a) 1
      (b) n
      (c) n - I
      (d) [n/2] where [.] is the bracket function
19. If Q, R, ((: are respectively the fields of rational numbers, real
      numbers and complex numbers then which one of the
      following algebraic structures is not a vector space?
      (a) R over the field Q (b)
      R over the field R
      (c) Q over the field R
      (d) C over the field C
20.   Let x = (3, 2, -\), Y = (2, 4, 1), z = (4, 0, -3) and w = (10, 4, -5)
      be vectors in R 3, a real vector space. Which one of the
      following is correct?
      (a) 2x + Z = w, y + Z = w
      (b) 2x - y = z, Y +. 2z = w
      (c) x + Z = w, 2x + Y = z
      (d) y + 2z = w, x - y = z
21. If V is the real vector space of all mappings from R to R, VI =
    {f E V I f(-x) = f(x)} and V2 = {f E V I f(-x) = -f(x)}, then
    which one of the following is correct?
    <a) Neither V I nor V 2 is a subspace of V
    (b) Viis a subspace of V, but V2 is not a subspace of
         V
     (c) V I is not a subspace of V, but V 2 is a subspace of
          V
     (d) Both V I and V 2 are subspaces of V
     Let F[x] be the ring of polynomials in one variable x over a
22.
     field F with the relation xn = 0, for a fixed n EN. What is the
     dimension of F[x] over F ?
    (a) I                            (b) n - 1
    (c) n                            (d) Infinite
23. Which one of the following is correct?
     The set S = {a + ib, c + id} is a basis for the vector space
        <C over R iff

       (a) ad - be = 0                (b) ad + be = 0
       (c) ad + be '" 0               (d) ad - be '" 0
24.    Let V be the vector space of all 2 x 2 matrices over the field


        R of real numbers and B =   [: : J . 1fT : V --> V is .linear
        transformation defined by T(A) = AB    -   BA, then what is the
        dimension of the kernel of T ?
        (a) 1                          (b) 2
        (c) 3                          (d) 4
 25.    What is the rank of the linear transformation T : R 3 ~ R 3 defined
        by T(x, y, z) = (y, 0, z) ?
      (a) 3                            (b) 2
      (c) 1                            (d) 0
26. Consider the vector space Cover R and let T : C .................... C
      be a linear transfonnation given by T(z) = Z. Then :which
      one of the following is correct?
      (a) T is one-one, but not onto.
      (b) T is onto. but not one-one
      (c) T is one-one as well as onto.
      (d) T is neither one-one nor onto.
27. If T is a linear transformation ftom a real vector. space R2 to a
       real vector space R3 such that T(x, y) = (x - y, y - x, "':x), then
       what is the nullity of T ?
      (a) 0                        .   (b) 1
      (c) 2                            (d) 3

                                                   [COSO      Si.O]
28. If n is a positive integer and A =         .
                                                                     .   then
                                                     -sinO cosO
       what is. A D equal to ?
              [ coS.O   -sin .0]               [ -cos.O    sin.O ]
         (a) sin nO cas nO             (b)     sin nO      cos nO

        [ COS .0        sin nO]                [cosnO      sin .0 ]
       (c) sin nO       - cas nO       (d)     - sin nO    cos nO
29.    If A and B are symmetric matrices of the same order, then
       which one of the following is not correct?
       (a) A + B is a symmetric matrix.
       (b) AB - BA is a symmetric matrix.
       (c) AB + BA. is a symmetric matrix.
       (d) A + AT and B + B T are symmetric: matrices.
                 3 -2
30. If A =                     satisfies the matrix equation A 2         - kA +
               [ 4 -2      ]
      21 = 0, then what is the value of k ?
      (a) 0                         (b) I
      (c:) 2                        (d) 3


                                                          1 b+c: b2 +C2

                                             1 c+a C2 +a2
31.   What is the value of the detenninant I 1 a+b a2 +b2                    I?

     (a) (a-b)(b-c)(c-a)          (b) (a+b)(b+c)(c+a)
     (c) abc                      (d) a + b + c
32. Under which one of the following conditions does the
                                           12 4           x        6
                                     :
       system of equations           .     212            y   =    4     have a
                                 [         1 2 a-4   ][       ]   [ z]
       unique solution?                       a
       (a) For all a E R             (b) a = 8
       (c) For all a E Z             (d) a ~ 8
33. Consider the equations 2x + 2y = 1 and 2x - y = lover
      Z J. What is the solution (x, y) ?
     (a) (1, 1) but not (2, 0)
     (b)(2, 0) but not (I, I)
     (c) Both (I, 1) and (2,0)
     (d) (1/2, 0)
34. Which one of the following is correct ?
     For different values of a and b, the straight line given by

      x(a + 2b) + y(a - 3b) = a          - b passes through
      (a) a conjugate point.                (b) a fixed point.
      (c) the origin.                       (d) None of the above

35. The line 3x + 2y = 24 meets the y-axis at A and the x-axis at S, and perpendicular bisector of AS meets the line through (0, -1)
      parallel to the x-axis at C. What is the area of the triangle ABC ?
      (a) 91 square unit             (b) 81 square unit
      (c) 61 square unit             (<I) 41 square unit

36. Consider the following statements :
      8 1 : The equation                             .
              ax2 + 2hxy + by2 + 2gx + 2fy + c = 0
             represents a pair of straight lines.
      82: The equation ax2 + 2hxy + by2 = 0 always represents
              a pair of straight lines passing through the origin. Which one of the following is correct?
      (a) If 81 is true, 82 is always true.
      (b) If SI is not true, then 82 is also not true.
      (c) 82 is always true and 81 implies 82 if c = O.
      (d) Both 81 and 82 imply each other.
40.   What is the equation of the plane which bisects the line joining
      the points (3, -2, 1) and (1, 4, -3) at right angles?
      (a) x - 3y + 2z + 3 = 0 (b) 3x - 2y + Z + 3 = 0
      (c) x + 4y - 3z + 2 = 0 (d) x - 3y + 2z + 2 = 0
      What is the equation of the plane which passes through the
      z-axis and is perpendicular to the line
       x-I y+2 z-3
      -=-=- ? cos9 sin 9 0 .

      (a) x + y tan 9= 0 (b)
      y + x tan 9 = 0
                   -
      (c) x cos 9 y sin 9 = 0 (d) x
      sin 9 -   y cos e = 0
42. A straight lin; LOn the XY.plane bisects-the angie between ox
      and OY. What are the direction cosines of L ?
      (a) < 1/.,/2, 1/.,/2, 0 > (b) < 1/2, .fi/2, 0 >
      (c) < 0, 0, 1 >                   (d) < 2/3, 2/3, 1/3 >
43. What is the equation of the cone with vertex at origin and
      passing through the circle x2 + y2 = 4, z = 2 ?
      (a) x2 + y2 + z2 = 4              (b) x2 + y2 - z2 = 0
      (c) x2 + y2 - z2 = 2              (d) x2 + y2 + z2 = 2
        ~ ~
44. If a,~b, c are non-zero vectors such that
        ~~~4~~
       (a x b)x c = a x (b x c), then which one of the
                following is correct?
           ~~
      (a) a and b are collinear
           ~~
       (b) a and c are collinear
      (c)   b and ~ are collinear
     (d) None of the above
45. Consider the following two statements :
                ~~~
      S1 :      a, b, c are non-zero, non-coplanar vectors
                        ~           ~
                ~ bxc ~,c=
                                                         ~
                                              ' cxa ~~ axb           ~       ~
                a= ,=                     b
      S2 :                  ~~~                        ~~~               -
                        (a b c)
                                                        .
                                                   (a b c)           (a b c)

               are non-coplanar
      Which one of the following is correct?
      (a) 81 implies 82 but 82 does not im~!y 8}
      (b) 8} does noUmply-S2 but 82 implies 81
      (c) 8-1 imPlies 82 and 82 implies 81
      (d) 81 does not imply 82 and 82 does not imply 8} What is the
46.   volume of the tetrahedron with vertices at (0,0,0), (I, I, I), (2, I,
      1) and (1, 2, 1)?
      (a) 1/6                       (b) Ii3
      (c) 1/2                       (d) 1
            ~
47. If r satisfies the equation
      ~ AAAAA
      r x (i + 2j + k) = i
            ~
                                  - k," then for any scalar m, what
      is r equal to ?
      (a) i + m(i + 2j + k) (c) k              (b) j + m (i + 2j + k)

      + m (i + 2j + k)
      (d) i -   k + m(i + 2j + k)
48. For the triangle OBC, one vertex 0 is the origin and the
                            .   ~   .position vectors of the other vertices B
      and C are b and
         c respectively and a, b, c are the lengths of the sides BC,
        OB and OC respectively. What is the position vector of the
        incentre of the triangle OBC ?

                b
                    -. -.                            -. -.
                    (a) b + c                        (b) b +
        c                                   C
                 -.b+c
                    -.                               a+b+c
                                                      -. -.
                 (c) c b +                            (d) b b +
        bc                                 cc
49.              a+b+c
       What is the range of the function
                                                     a+b+c

       f(x) = log2 {(sin x - cos x + 3 .fi )/.fi} ?
       (a) [I, 2J                   (b) [0, I]
       (c) (1, 2)                   (d) (0, I)
50. I. 1m I. (x+3sinx- x3 -k sinh x) .
        f                     2     3.      eXIsts, then w at IS. t e
                                                           h         h
          x~o I-cosx + X -3x
      value of k ?
      (a) -I                       (b) 2 (d)
      (c) 3                        4

                        {Sin(a + 2)x + sin x} / x x < 0
51. Iff(x) = b,                                  X= 0

                     { {(x + 3x2)1/3   - x1/3} / x4/3, x> 0
      is continuous at x = 0, then what are the values of a and b
      respectively?
      (a)   - I, - I                     (b) 1,-1
      (c) 2, I                           (d) -2, I

52. Let f{x) = x"[xJ for real x. f(x) is differentiable at the origin
     if n is equal to which one of the following?
      (a) -J<                       (b) 0
      (c) any real number           (d) any positive integer
53.   What is the maximum value of
      y =" sin3 x cos x, 0 < x < 1t ?

      (a) -3.,fj /16 (c)            (b) 3.,fj / 4 (d)
      -3/16                           3.,fj /16
54.                -
      Match List I with List - II and select the correct answer
      using the code given below the lists:
                     List,.. I                              -
                                                        List II
      A. The function x3 - 6x2 - 36x + 7            1. x = -2
           increases when
      B. The function x3 - 6x2 - 36x + 7            2 x= 6
           is maximum at
      C. The function x3 - 6x2 - 36x + 7            3. x < - 2 or x>6
            is minimum at                             4. -2 < x < 6
      D. The function x3 - 6x2 - 36x + 7
           decreases when
              ABC DAB C D
      (a) 4 2           1 3             (b) 3     1 2 4
      (c) 3 2           I      4        ( d) 4    1 ~ 3
55.   If 4a + 2b + c = 0 , then the equation 3ax2 + 2bx + c = 0 has at
      least one real root lying between which of the following?
      (a) 0 and 1                     (b) 1 and 2
      (c) 0 and 2                     (d) None of the above
      Under which one of the folJowing conditions does the
56.
      function f(x) = {(x2)m sin (x-2)n} x * 0, n > 0 and f(O) = 0
      have a derivative at x = 0 ?
      (a) m ~ -1/2                   (b) m> 0
      (c) m > 1/2                    (d) m ~ 1/2                         j

57.
      If the tangent to the curve f(x) = x2 at any point (e, fee)) is    I
      paralJel to the line joining the points (a, f(a)) and (b, f(b))
      on '
      the curve, then which one of the following is correct? (a) a, c, b
      are in A.P.
      (b) a, c, b are in G.P.
      (c) a, c, b are in H.P.
      (d) a, c, b do not follow definite sequence
58.   What is the maximum area of the rectangle whose sides pass
      through the angular points of a given rectangle of sides 'a' and
      'b' ?
      (a) (a + b)2/2                  (b) (a + b)2 (d)
      (c) (a2 + b2)/2                 (a2 + b2)
59. What is the abscissa of the point at which the tangent to the
    curve y = eX is parallel to the chord joining the extremities of
    the curve in the interval [0, I] ?
    (a) 1/2                          (b) in (lie)
    (c) in (e I)
               ~                     (d) lie
60. What is the subnormal at x = 1t/2 on the curve y = x sin x?
    (a) I                            (b) 2/1t
    (c) 1t I 2                       (d) 2
    Which one of the following is correct? The
61.
    inclined asymptotes of the curve
    x3 - xy2 - 2xy + 2x - y = 0 are themselves
    (a) perpendicular
    (b) parallel
    (c) inclined at an angle 1t/3
    (d) inclined at an angle 1t/4
62: Which one of the properties pertaining to the tangent at any
    point on the curve x2/3 + y2/3 = a2/3 is correct? . (a) Sum of its
                                                                           --=
    intercepts made with the coordinate axes
          is constant
     (b) It encloses a triangle of constant area with the
          coordinate axes
     (c) Length of its portion intercepted between the
          coordinate axes is constant
      (d) It always passes through the origin
63. What is the least absolute value of the radius of curvature for
      the curve y = In x ?
      (a)   3..[j                         (b) 2..[j
      (c) ..[jl.,fi                       (d) 3..[j 12
                                   1t/
                                   2

                                   f   5sinx + 3cosx dx
64.   What is the value of                  sin x + cosx ?
                                   0
      (a) 0                               (b) n/2
                                                          x
65.   (c) 4n                              ( d) 2n
                    T~e maximum value off(x), where f(x) =    J   sin {x(l-
      x)} dx
                                                     0
66.   occurs at which one of the following points?
      (a) x = 0                        (b) x = I
      (c) x = - I                      (d) None of the above
      What is the volume of solid generated, when the area of the
                                       (b) 12n (d)
      ellipse (x2/9) + (y2/4) = I (in the first quadrant) is revolved
                                       6n
      about y-axis?
      (a) 16n
           11
67.   IfJ
      (c) 8nxm(1- x)n dx =     Jxn(l- x)P dx, then what is p equal
           00
      to ?
      (a) 2n                           (b) m
      (c) m + n                        (d) mln
68.   What is the area of the region bounded by the curve 2y =
        2 - 3x - 2x2 and the x-axis?
        (a) 125/48 square unit (b) 4 square unit
        (c) 3 square unit          (d) 125/24 square unit

                    X3 sin x cosxl

 69.    If f(x) = .6        -1     0
                                             , where p is a constant, then
                    p       p2   p3

                                 d3
        what is the value of -r {f(x)} at x = 0 ?
                                 dx
       (a) P                               (b) p + p2
       (c) p + p3                          (d) Independent of p
70.    What are the order and degree respectively of the differential
       equation of the family of curves y2 = 2c (x + ~), where c is an'
       arbitrary constant?
       (a) 1, 1                      (b) 1, 2
       (c) I, 3                      (d) 2, 1

                                                                d2 d
71.
        solution of the differential equation
                                       <
                                                                   ;      y
                                                                What is,the
                                                                dx = 2dx
       + 2y = 0, with the given conditions y(O) = 0 and y'(O) = I ?
       (a) y = e-X cos x                    (b) y = e-X sin x
       (c) y = (cos x + sin x) e-X (d) y = sin x
72.
       What is the solution of the differential equation (1 + ex/y)

       dx + ex/Y (1- ~) dy = 0 ?

       (a) x + y eX/Y =c                   (b) y + x eX/Y = c
       (c) x - y eX/Y = c                  (d) None of the above
73.
       The singular solution of the differential equation y = px +
      f(p) will be obtained by eliminating p between the equation y
      = px + f(p) and which one of the following equations?
                     df                            dv                 df
      (a) x + = 0                          (b) .................... = X +
                     dp                            dp                 dp
            dy   .                                         dy df
        (c) - =       P                                 (d) - = p +
           dx                                              dx dp
74.
      Consider the following statements in respect of the

      differential equation 2xy       :   = yl - xl.
      1. The differential equation is a homogeneous equation 2. The
      curve represented by the differential equation is
          a family of circles
      3. The differential equation of its orthogonal trajectories           'I
          . dy 2xy
          IS -            =   2   2
                dx x-y
      Which of the statements given above are correct?
      (a) 1 and 2 only            (b) 1 and 3 only
75.   (c) 2 and 3 only            (d) 1,2 and 3
      What are the orthogonal trajectories of the system of curves
      (:Y    =~?
      (a) 9a (y + c)l = :J:2 x3/2 (b) 9a (y + c)l = :J:2 xll3
      (c) 9a (y + c)3 = 4x2 (d) 9a (y + c)2 = 4 x3
      From a square lamina ABCD whose diagonals meet at 0, the
76.
      triangle AOB is cut and the remaining part is hung up at D. In
      the position of equilibrium, how much angle does DC make
      with the vertical?
      (a) tan-l(7/9) (c)              (b) tan-l (5/9) (d)
      45°                             30°
77                                                 D
.
                                                        B




              A                                    0


      A pillar OD is to be pulled down by tying a rope of length 1= AB
      to some point B of the pillar and then puIling the rope with a
      force F as shown in the above figure. F will have
      maximum moment about 0 when OB equals to which one of the
      following?
      (a) J2 I                           (b) I /   J2
      (c) fi I                             (d) I /     fi

                 B
                                         ck;

78.


              A                      D
                 ~
      A force F, having magnitude of 10 dyne, is applied on the
      comer C of a rectangular plate ABCD, as shown in the figure
      above. If AB = 8 em, AD = 12 em, then what is the moment
          -+
      of F about A ?
      (a) 20 (-2 + 3.fi) x 1O-7Nm (b) 20
      (-2 + 3.fi) x 10-5 Nm (c) 20 (2. +
      3 .fi) x 10-7 Nm
      (d) 20 (2 + 3.fi) x 10-5 Nm

79.   A heavy spherical ball of weight W is on a smooth inclined
      plane (a. = angle of inclination of the plane to the horizontal).
      A force of magnitude P is applied through the centre of the ball
      in order to maintain the ball at rest. What is the value ofP?


      (a) P = W JI + cos2 a.
                                     (b) P = W cos a. (d) P =
      (c) P = W sin a.
                                    W ~I+sin2a.
80.   The weight of a triangular lamina ABC is 9 g. What is the
      additional weight to be placed at A so that the new centre of
      gravity divides the median through A in the ratio 3 : 4 ?
      (a) 2 g                       (b) 3 g
      (c) 4 g                       (d) 5 g
81.   Two spheres of radii 6 em, 3 em are firmly united. The two
      spheres are solid and of the same material. What is the distance
      of the centre of gravity of the whole body from the centre of
      the larger sphere?
      (a) 1 em                       (~) 2 cm
      (c) 3 em                       (d) 4 em
82.   If the angle of friction is A, then what is the greatest height at
      which a particle can rest inside a hollow sphere of radius a?
      (a) a sin A
                                       (b) a (1 - cos A)
      (c) a tan A.                      (d) a   (1 - sin A.)
83.
      UI                                                        U2




                     A                              B

      Two points A and B have velocities ul and u2 as shown in the
      figure above. If AB = d, what is the angular velocity of A
      relative to B ?
      (a) (ul cos al - u2 cos a2)/d
      (b) (ul cos al + u2 COS a2)/d
      (c) (ul sin al - u2 sin a2)/d
      (d) (ul sin al + u2 sin a2)/d
84.   Two particles are projected vertically upwards from a place at
      an interval of 2 seconds. If the first and the second particle
      attain the respective greatest heights HI and H2 simultaneously,
      then which one of the following is correct?

      (a)   ~   = (.jH;   +   fii)   (c) (b) .jH; = (JI-G + fii) (d)
      ~HIH2 = 2g                         ~HI / H2 = 2
85.   A particle of unit mass is constrained to move in a smooth
      circular path of radius a with constant speed. If now an
      additional radial force of magnitude P acts on the particle, how
      does the kinetic energy (E) of the particle change?
      (a) E changes by Pa/2 (b) E changes by               Ji   Pa (c) E
      changes by Pa/4 (d) E changes by 2 Pa
86.   A smooth heavy bead moves along a wire, which is bent in a
      circle of radius a in a vertical plane. The bead starts from rest
      from the position where the radius to it makes an angle of 60°
      with the upward vertical. What is the velocity of the bead
      when it reaches the lowest point (the wire is fixed in space) ?
      (a) ~3ga

      (c) 2jii;                      (b) ~2ga (d)

                                     ~5ga
87.   A particle is projected with velocity v at an angle « 45°) to
      the horizontal and reaches a point on the horizontal distant R
      from the point of projection. What is the greatest height (h)
      attained during the path of the projectile? .




      (a) h =
                  V2

                     [    F g2R2               v2


                  4g 1- ~l7" ) (b))] h = 4g 1 + l7"
                                                [
                                                         (g2R2

                                                                  )]


      (c) h=
                  v2
                    [     F g2R2

               2g l-~l~) (d) h=)] l+Vl7")
                                2g
                                               v2

                                                    [    F
88. A particle is executing simple harmonic motion and its
                                                           g2R2

                                                                  )]
      displacement from its mean position is given by x = a cos (nt +
      k), where t denotes the time and a, Ii, k are positive constants.
      Under what condition will the speed of the particle be
      maximum?
      (a) t = (2p + 1) 1t 12n, p being an integer
      (b) t = (2p + 1) 1t/2n - (kin), p being an integer
      (c) t = (2p + 1) 1t/2n + (kin), p being an integer
      (d) t = 'p1t/n - (kin), p being an integer
89.   A particle whose weight on the surface of the earth is W, falls
      JQ the surface of the earth from a height equal to the
      diameter 2R of the earth. What is the work done by the earth's
      attraction?
      (a) 2RW (c)                  (b) 2RW/3
      4RW/3                        (d) 3RW/2

                               . xY - yx
90.             What is the value of hm x y ?
                              x-+y X -y

           I+In y                        1- In y
      (a) I-Iny                      (b) 1 + In y

           I+Iny                          -I-In y
      (c) I+In y                         (d) 1 -In y

91. A floppy with 1.44 MB capacity can store the infonnation
      equivalent to which one of the following?
      (a) 1-44 x 26 bytes          (b) 1.44 x 210 bytes
      (c) 1.44 x 220 bytes         (d) 1.44 x 1024 bytes
92. Under what conditions of the inputs A and B, will the output in
     the gates for operations OR and XOR be different?
     (a) A = I, 8 = 0                (b) A = 0, 8 = I
     (c) A = 0, B = 0                (d) A = 1, B = 1
93. Step I :              get A, B
     Comment:             A (i, j) and B(i, j) are m x nand n x p
                          matrices
      Step 2 :            For i = 1 to m
                          do
                          for j = I to P
                          do
                          C(i,j) ~ 0
                          For k = 1 to n
                          do
                          C(i,j) ~ X
       Step 3 :               Output C
       Comment:               C = C(i, j) is the product matrix
                              AB of the order m x p
       What is X in the above algorithm ?
       (a} C(i, j) + ,A(i, k) . B(k, j)
       (b) C(i, j) + A(i, k) . BU, k)
       (c) A(i, k) + B(k, j)
       (d) C(i, j) + A(i, j) . B(i, j)
94.    What is the decimal equivalent of the hexadecimal number
       FF?
       (a) 225                      (b) 245 (d)
       (c) 255                      256
95.    Which one is called "coincidence detector" ?
       (a) OR gate                       (b) NAND gate
       (c) NOT gate'                     (d) AND gate
Directions: The following 5 (Five) items consist of two statements :
one labelled as the 'Assertion (A)' and the other as 'Reason (R)'. You
are to examine these two statements carefully and select the answers
to these items using the codes given below:
       (a) Both A and R are individually true and R is the
               correct explanation of A
       (b) Both A and R are individually true but R is not the
               correct explanation of A
       (c) A is true but R is false
       (d) A is false but R is true
96. Let n ~ 3, n be odd
       Assertion (A) : For any i = 1,2, ............. , n - 1; if aI' a2' ............. ,
                          an are the roots of the equation xn xi - 1 =     -
                          0, then (1 + at) (1 + a2) .... (1 + an) = 1
      Reason (R)          : If at, .......... , an are the roots of the equation,
                            xn - x-I = 0, then (1 + at) (l + a2) .... (1 + an)
                           = 1.
97.   Assertion (A) : There is at least one cyclic group of order
                       100 which has only 5 subgroups.
               Reason (R) : A fmite cyclic group of order m has a
                       unique subgroup of order n, where n is a
                       divisor of m.

98.                                                            x
      Assertion (A) : The function f(x) = 1 + Ixl is not
                       differentiable at x = O.
      Reason (R) : I x I and hence (1 + I x I) is not differentiable
                       at x = O.
99.   Assertion (A) : The function y = x2/4 is a singular solution
                                        2
                                  dy dy

                            0.
                                  () of dx      -   x dx + y   =
      Reason (R)          : The general solution of the given equation is y
                            = cx - c2 and the given solution cannot be
                            obtained by assigning a definite value to c in
                            the general solution.

                             . .12
100. Assertion (A):   I    005. X dx   =2   I   co;. x dx
                             00
      Reason (R)          : The integrand is an even function.


  Note: The publisher is not responsible for any mistake, we have
  tried our best to collect the correct data/answers. All disputes are
  subject to the exclusive jurisdiction of Delhi courts only.

				
DOCUMENT INFO
Shared By:
Categories:
Tags: maths
Stats:
views:45
posted:7/26/2012
language:English
pages:22
Description: maths