JEE Advance - Mathematics (1988)

  • 1
    Urn $$A$$ contains $$6$$ red and $$4$$ black balls and urn $$B$$ contains $$4$$ red and $$6$$ black balls. One ball is drawn at random from urn $$A$$ and placed in urn $$B$$. The one ball is drawn at random from urn $$B$$ and placed in urn $$A$$. If one ball is now drawn at random from urn $$A$$, the probability that it is found to be red is ................
    Atsakymas
    (A)
    32/55
  • 2
    One hundred identical coins, each with probability, $$p,$$ of showing up heads are tossed once. If $$0 < p < 1$$ and the probability of heads showing on $$50$$ coins is equal to that of heads showing on $$51$$ coins, then the value of $$p$$ is
    Atsakymas
    (D)
    $$51/101.$$
  • 3
    For two given events $$A$$ and $$B,$$ $$P\left( {A \cap B} \right)$$
    Atsakymas
    B
    C
    A
  • 4
    A box contains $$2$$ fifty paise coins, $$5$$ twenty five paise coins and a certain fixed number $$N\,\,\left( { \ge 2} \right)$$ of ten and five paise coins. Five coins are taken out of the box at random. Find the probability that the total value of these $$5$$ coins is less than one rupee and fifty paise.
    Atsakymas
    (A)
    $$\,1 - {{10left( {N + 2} ight)} over {\binom{N + 7}{5}}}$$
  • 5
    The components of a vector $$\overrightarrow a $$ along and perpendicular to a non-zero vector $$\overrightarrow b $$ are ......and .....respectively.
    Atsakymas
    (C)
    $$\left( {\frac{{\overrightarrow {a,} .\,\overrightarrow b }}{{{{\left| {\overrightarrow b } \right|}^2}}}} \right)\overrightarrow b \,\,\text{and}\,\,\overrightarrow a - \left( {\frac{{\overrightarrow a \,.\,\overrightarrow b }}{{{{\left| {\overrightarrow b } \right|}^2}}}} \right)\overrightarrow b $$
  • 6
    Let $$\overrightarrow a ,\overrightarrow b ,\overrightarrow c ,$$ be three non-coplanar vectors and $$\overrightarrow p ,\overrightarrow q ,\overrightarrow r,$$ are vectors defined by the relations $$\overrightarrow p = {{\overrightarrow b \times \overrightarrow c } \over {\left[ {\overrightarrow a \overrightarrow b \overrightarrow c } \right]}},\,\,\overrightarrow q = {{\overrightarrow c \times \overrightarrow a } \over {\left[ {\overrightarrow a \overrightarrow b \overrightarrow c } \right]}},\,\,\overrightarrow r = {{\overrightarrow a \times \overrightarrow b } \over {\left[ {\overrightarrow a \overrightarrow b \overrightarrow c } \right]}}$$ then the value of the expression $$\left( {\overrightarrow a + \overrightarrow b } \right).\overrightarrow p + \left( {\overrightarrow b + \overrightarrow c } \right).\overrightarrow q + \left( {\overrightarrow c + \overrightarrow a } \right),\overrightarrow r $$ is equal to
    Atsakymas
    (D)
    $$3$$
  • 7
    Let $$OA$$ $$CB$$ be a parallelogram with $$O$$ at the origin and $$OC$$ a diagonal. Let $$D$$ be the midpoint of $$OA.$$ Using vector methods prove that $$BD$$ and $$CO$$ intersect in the same ratio. Determine this ratio.
    Atsakymas
    (B)
    2:1
  • 8
    Evaluate $$\int\limits_0^1 {\log \left[ {\sqrt {1 - x} + \sqrt {1 + x} } \right]dx} $$
    Atsakymas
    (D)
    $$\frac{1}{2} \left[\log 2 + \frac{\pi}{2} - 1\right]$$
  • 9
    If $$P=(1, 0),$$ $$Q=(-1, 0)$$ and $$R=(2, 0)$$ are three given points, then locus of the point $$S$$ satisfying the relation $$S{Q^2} + S{R^2} = 2S{P^2},$$ is
    Atsakymas
    (D)
    a straight line parallel to y-axis.
  • 10
    $$\,{\left| {a{z_1} - b{z_2}} \right|^2} + {\left| {b{z_1} + a{z_2}} \right|^2} = .........$$
    Atsakymas
    (E)
    $$\left( {{a^2} + {b^2}} \right)left( {{{\left| {{z_1}} \right|}^2} + {{\left| {{z_2}} \right|}^2}} \right)$$
  • 11
    The cube roots of unity when represented on Argand diagram form the vertices of an equilateral triangle.
    Atsakymas
    (B)
    FALSE
  • 12
    $$\left| {\matrix{ {1 + {{\sin }^2}\theta } & {{{\cos }^2}\theta } & {4\sin 4\theta } \cr {{{\sin }^2}\theta } & {1 + {{\cos }^2}\theta } & {4\sin 4\theta } \cr {{{\sin }^2}\theta } & {{{\cos }^2}\theta } & {1 + 4\sin 4\theta } \cr } } \right| = 0$$ are
    Atsakymas
    A
    C
  • 13
    Solve $$\left| {{x^2} + 4x + 3} \right| + 2x + 5 = 0$$
    Atsakymas
    A
    D
  • 14
    Total number of ways in which six ' + ' and four ' - ' signs can be arranged in a line such that no two ' - ' signs occur together is.....................................
    Atsakymas
    (C)
    35
  • 15
    There are four balls of different colours and four boxes of colours, same as those of the balls. The number of ways in which the balls, one each in a box, could be placed such that a ball does not go to a box of its own colour is.......................
    Atsakymas
    (B)
    9
  • 16
    Let $$R$$ $$ = {\left( {5\sqrt 5 + 11} \right)^{2n + 1}}$$ and $$f = R - \left[ R \right],$$ where [ ] denotes the greatest integer function. Prove that $$Rf = {4^{2n + 4}}$$
    Atsakymas
    A
    D
  • 17
    The sum of the first n terms of the series $${1^2} + {2.2^2} + {3^2} + {2.4^2} + {5^2} + {2.6^2} + .........$$ is
    $$n\,\,{\left( {n + 1} \right)^2}/2,$$ when $$n$$ is even. When $$n$$ is odd, the sum is .............
    Atsakymas
    (B)
    $${{{n^2}left( {n + 1} ight)} \over 2}$$
  • 18
    Sum of the first n terms of the series $${1 \over 2} + {3 \over 4} + {7 \over 8} + {{15} \over {16}} + ............$$ is equal to
    Atsakymas
    (C)
    $$n + {2^{ - n}} - 1$$
  • 19
    If the first and the $$(2n-1)$$st terms of an A.P., a G.P. and an H.P. are equal and their $$n$$-th terms are $$a,b$$ and $$c$$ respectively, then
    Atsakymas
    B
    A
    D
  • 20
    The lines $$2x + 3y + 19 = 0$$ and $$9x + 6y - 17 = 0$$ cut the coordinates axes in concyclic points.
    Atsakymas
    (B)
    FALSE
  • 21
    The value of the expression $$\sqrt 3 \,\cos \,ec\,{20^0} - \sec \,{20^0}$$ is equal to
    Atsakymas
    (C)
    4
  • 22
    Lines$${L_1} = ax + by + c = 0$$ and $${L_2} = lx + my + n = 0$$ intersect at the point $$P$$ and make an angle $$\theta $$ with each other. Find the equation of a line $$L$$ different from $${L_2}$$ which passes through $$P$$ and makes the same angle $$\theta $$ with $${L_1}$$.
    Atsakymas
    (D)
    $$\left( {{a^2} + {b^2}} \right)\left( {\ell x + my + n} \right) - 2\left( {a\ell + bm} \right)left( {ax + by + c} \right) = 0$$
  • 23
    If the circle $${C_1}:{x^2} + {y^2} = 16$$ intersects another circle $${C_2}$$ of radius 5 in such a manner that common chord is of maximum lenght and has a slope equal to 3/4, then the coordinates of the centre of $${C_2}$$ are.............................
    Atsakymas
    (E)
    (9/5, -12/5) or (-9/5, 12/5)
  • 24
    If a circle passes through the point (a, b) and cuts the circle $${x^2}\, + \,{y^2}\, = \,{k^2}$$ orthogonally, then the equation of the locus of its centre is
    Atsakymas
    (A)
    $$2\,ax\, + \,2\,by\, - \,({a^2}\, + \,{b^2}\, + \,\,{k^2})\, = \,0$$
  • 25
    The equations of the tangents drawn from the origin to the circle $${x^2}\, + \,{y^2}\, - \,2rx\,\, - 2hy\, + {h^2} = 0$$, are
    Atsakymas
    A
    C
  • 26
    If $${y^2} = P\left( x \right)$$, a polynomial of degree $$3$$, then $$2{d \over {dx}}\left( {{y^3}{{{d^2}y} \over {d{x^2}}}} \right)$$ equals
    Atsakymas
    (C)
    $$P\left( x \right)P''\left( x \right)$$
  • 27
    If the angles of a triangle are $${30^ \circ }$$ and $${45^ \circ }$$ and the included side is $$\left( {\sqrt 3 + 1} \right)$$ cms, then the area of the triangle is ...............
    Atsakymas
    (B)
    $$\frac{\sqrt{3} + 1}{2}$$
  • 28
    A sign -post in the form of an isosceles triangle $$ABC$$ is mounted on a pole of height $$h$$ fixed to the ground. The base $$BC$$ of the triangle is parallel to the ground. A man standing on the ground at a distance $$d$$ from the sign-post finds that the top vertex $$A$$ of the triangle subtends an angle $$\beta $$ and either of the other two vertices subtends the same angle $$\alpha $$ at his feet. Find the area of the triangle.
    Atsakymas
    (A)
    (d tan β - h)√(h² cot² α - d²)
  • 29
    Investigate for maxima and minimum the function $$$f\left( x \right) = \int\limits_1^x {\left[ {2\left( {t - 1} \right){{\left( {t - 2} \right)}^3} + 3{{\left( {t - 1} \right)}^2}{{\left( {t - 2} \right)}^2}} \right]} dt$$$
    Atsakymas
    B
    C
  • 30
    Where [ ] denotes the greatest integer function, equals .............
    Atsakymas
    (C)
    2 - √2
  • 31
    The value of the integral $$\int\limits_0^{2a} {[{{f\left( x \right)} \over {\left\{ {f\left( x \right) + f\left( {2a - x} \right)} \right\}}}]\,dx} $$ is equal to $$a$$.
    Atsakymas
    (B)
    FALSE
  • 32
    Find the area of the region bounded by the curve $$C:y=$$
    $$\tan x,$$ tangent drawn to $$C$$ at $$x = {\pi \over 4}$$ and the $$x$$-axis.
    Atsakymas
    (D)
    $$\frac{1}{2} [\log 2 - \frac{1}{2}]$$ sq. units