Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

Let Gamma be a circle with diameter AB and centre O.Let l be the tangent toGamma at B.For each point M onGamma different from A,consider the tangent t at M and let it interest l at P.Draw a line parallel to AB through P intersecting OM at Q.The locus of Q as M varies over Gammais

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an ARC of a circle
a parabola
an arc of an ellipse
a branch of a hyperbola

Solution :
EQUATION of tangent at M, `x cos theta + y sin theta =r`
PUT x=r, to get y-coordinate of point P.
`r cos theta + y sin theta =r`
`implies y=(r(1-cos theta))/(sin theta)=(r .2.sin^(2)"" theta/2)/(2.sin ""theta/2.cos"" theta/2)=r tan ""theta/2`
`:. P=(r,rtan""(theta)/(2))`
`:.` Q has y-coordinate same as point P
`:. K= r tan""theta/2 impliestan""(theta)/(2)=(K)/(r)`
Slope of tangent at `M= - cot theta`
Slope of `OQ=(K)/(h)`
`:.(K)/(h),(- cot theta)= -h implies than theta =(K)/(h)`
`implies (2 tan""(theta)/(2))/(1- tan^(2)""(theta)/(2))=(K)/(h ) implies(2. (K)/(r))/(1-(K^(2))/(r^(2)))=(K)/(h)`
`implies (2h)/(r)=1-(K^(2))/(r^(2)) implies(2h)/(r)=(r^(2)-K^(2))/(r^(2))`
`implies 2hr=r^(2)-K^(2)`
`implies y^(2)=r^(2)-2Kr`
`y^(2)= - 2r(x-r//2)`
`:.` Parabola
2.

Treating x as dependent variable, find the line of best fit for the following data : {:(x, 15, 12, 11, 14, 13),(y, 26, 28, 24, 22, 30):} Hence, predict the value of y when x = 10

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ANSWER :`24 . 6 `
3.

STATEMENT - 1 : If n is even, .^(2n)C_(1)+.^(2n)C_(3)+.^(2n)C_(5)+"….."+.^(2n)C_(n-1) = 2^(2n-1). STATEMENT - 2 : .^(2n)C_(1) + .^(2n)C_(3)+ .^(2n)C_(5)+ "……"+ .^(2n)C_(2n-1) = 2^(2n-1)

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STATEMENT - 1 is true, STATEMENT - 2 is true and STATEMENT - 2 is CORRECT explanation for STATEMENT - 1.
STATEMENT - 1 is true, STATEMENT - 2 is true and STATEMENT - 2 is not correct explanation for STATEMENT - 1.
STATEMENT-1 is true, STATEMENT-2 is FALSE
STATEMENT-1 is false, STATEMENT-2 is true

Answer :A
4.

int_(1)^(0)((tan^(-1)x)/x + (lnx)/(1+x^(2))) dx is equal to

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`1/e_(tan^(-1)e)`
`tan^(-1)e`
`ETAN^(-1) (1/e)`
`tan^(-1)(lne)`

Solution :`int_(1)^(e)tan^(-1)X. 1/x dx + int_(1)^(e)(ln x)/(1+x^(2)) dx`
`=(tan^(-1) x ln x)_(1)^(e) - int_(1)^(e) 1/(1+x^(2)) ln dx + int_(1)^(e) (ln x)/(1+x^(2)) dx`
`=tan^(-1)(e). Lne - tan^(-1)(1).ln1`
`= tan^(-1)(e)`
5.

A car completes the first half of its journey with a velocity V_(1) and the remaining half with a velocity V_(2). Then the average velocity of the car for the whole journey is

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`(V_(1) + V_(2))/(2)`
`sqrt(V_(1) + V_(2))`
`(2V_(1)V_(2))/(V_(1) + V_(2))`
`(1)/(V_(1)) + (1)/(V_(2))`

Answer :C
6.

Of the following the one which is not a statement is

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2+3=4
Moon REVOLVES AROUND the sun
6 has four DIFFERENT PRIME factors
Read the question carefully

Answer :D
7.

If the lines (x-2)/(k)=(y-8)/(-3)=(z+5)/(9) and (x-5)/(1)=(y+2)/(1)=(z+5)/(k) have same direction then k = .........

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3
-3
`1/3`
`-1/3`

ANSWER :B
8.

State the converse, inverse and contrapositive of If Gopal is clever, then he is rich propositions. Stating it as a conditional, wherever necessary.

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Solution :CON :If Gopal is RICH is rich, then he is clever.
INV: If Gopal is not clever, then he is not rich.
Cont : If Gopal is not rich, then the is not clever.
9.

Two numbers X and Y are chosen at random from the set {1,2,……3n} . Find the probability that X^(2)-Y^(2) is divisible by 3.

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ANSWER :`(5n-3)/(3(3n-1))`
10.

Find (dy)/(dx) in the following : ax+by^(2)= cos y.

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ANSWER :`-(a)/(2BY+ SIN y)`.
11.

If P(A)=(6)/(11), P(B) =(5)/(11) and P(A cup B)=(7)/(11), find (i) P(A cap B) (ii) P (A|B) (iii) P(B|A)

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Answer :`(i) (4)/(11),(ii) (4)/(5), (III) (2)/(3)`
12.

Integrate the functions (sin^(8)x-cos^(8)x)/(1-2sin^(2)xcos^(2)x)

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ANSWER :`-1/2sin2x+C`
13.

If a line is drawn through a point A(3,4) to cut the circle x^(2)+y^(2)=4 at P and Q then AP .AQ=

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ANSWER :`S_(11)`
14.

Solvetheequation 3x^3 -26 x^2 + 52 x-24 =0 the rootsbeinginG.P

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ANSWER :`(a) 2/3 ,2,6"" (B )1/4,1/2,1 "" (C ) 1/2 ,(-2)/(3),8/9`
15.

A tangent to thecurve y=1 -x^(3) is drawn so thatthe abscissa x_(0) of thepoint of tangency belongs to theinterval (0,1].Thetangent at x_(0) meetsthe x-axisat A & Brespectively . Then find the minimum area of the triangle OAB where O is the origin

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ANSWER :`(4sqrt(3))/(9)`
16.

Let f(x)={(xsin((pi)/x), "at" xgt0),(0,"at"x=0):}

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`f^(')(x)` VANISHES atleast once in `[1/3,1/2]`
`f^(')(x)` vanishes atleast once in `[1/4,1/2]`
`f^(')(x)` satisfies Roll's THEOREM on `[0,1]`
`f^(')(x)` vanishes atleast once in `[1/(k+1),1/k]` for every `KepsilonN`

Solution :`f(x)` satisfies ROOL's theorem on `[1/(k+1),1/k],KepsilonN`
`:.f^(')(x)=0` on each interval `[1/(k+1),1/k],KepsilonN`
17.

Solve : sin["sin"^(-1)1/5+cos^(-1)x] = 1 .Find x.

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`(PI)/(2)`
1
`-1`
NONE of these

SOLUTION :N/A
18.

At what delta gt 0does the relation|int_(0) pisin x dx - sum_(i=0)^(n-1)sin zeta _(k) Delta x_(k)| lt 0 . 001 follow from the inequalitymax Deltax_(i) lt delta

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ANSWER :`2 DELTA LT 0.001, IE, delta lt 0.0005`
19.

The position vectors of the vertices, A,B,C of a tetrahedron ABCD are hati+hatj+hatk,hati.3hati. The altitude from vertex D to opposite face ABC meets the median line AF of DeltaABCat the point E. IF AD=4 and volume of tetrahedron is (2sqrt2)/3 then barE is

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`3hati-hatj-hatk`
`-hati+3hatj+3hatk`
`3hati-3hatj-hatk`
`-hati+3hatj+hatk`

ANSWER :A::B
20.

A factor o |((a-x)^(2),(b-x)^(2),(c-x)^(2)),((a-y)^(2),(b-y)^(2),(c-y)^(2)),((a-z)^(2),(b-z)^(2),(c-z)^(2))| is

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`a+b`
`x+y`
`x-y`
none

Answer :C
21.

The smallest positive integer n for which ((z-1)/(z+1))=k , where k is non-zero real, is

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a circle with center on y-axis
a circle with center on x-axis
a STRAIGHT line parallel to x-axis
a straight line making `pi//3` ANGLE with the x-axis.

Answer :c
22.

n-sqrt(2n-22)=1 Given the equation above, whichof the following is a possible value of n? I.7 II. -3 III. -5

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I only
III only
I and III only
II and III only

Answer :A
23.

Solve the inequality (5x)/(2)+(3x)/(4) ge (39)/(4) , when x is a real number.

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ANSWER :The SOLUTION SET is [3, `OO`)
24.

A tangent to the hyperbola meets x-axisat P and y-axis at Q. Lines PR and QR are drawn such that OPRQ is a rectangle (where O is the origin) then R lies on

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`(4)/(X^(2))+(2)/(y^(2))=1`
`(2)/(x^(2))-(4)/(y^(2))=1`
`(2)/(x^(2))+(4)/(y^(2))=1`
`(4)/(x^(2))-(2)/(y^(2))=1`

ANSWER :d
25.

int(1)/(sinx-cosx)dx

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Answer :`(1)/(SQRT(2))log|tan((X)/(2)-(PI)/(8))|+C`
26.

If 5th term of the expansion (root(3)(x) - 1/x)^n is independent of x then n =

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16
12
8
4

Answer :A
27.

Find the coordinates of the foot of the perpendicular drawn from the origin to the plane 2x – 3y + 4z - 6 = 0.

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ANSWER :`((12)/(29),(-18)/(29),(24)/(29))`
28.

Showthat thelines (x-1)/(2)=(y+1)/(3) "and" (x+1)/(5)=(y-2)/(2),z=2 do notintersect each other .

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<P>

SOLUTION :Theequationsof the givenlines are
`(x-1)/(2)=(y+1)/(3)=(z-0)/(1)=lambda`(say)
`(x+1)/(5)=(y-2)/(1)=(z-2)/(0)=mu`(say)
Anypoint onthe LINES(i) is`P(2lambda +1, 3lambda -1, lambda)`
Any POINTON the line (ii) is`Q (5mu-1,mu+2,2)`
If THELINES (i)and (ii) intersectthen Pand Qmustcoincide forsomeparticularvalues of `lambda " and' mu`
This gives
`2lambda+1 =5mu -1, 3lambda -1=mu+2 " and"lambda=2`
`rArr {underset(lambda=-3)underset(3lambda -mu=3)(2lambda -5mu =-2)`
Putting`lambda=2` in (iv)we get `mu =3`
Clearly`lambda =2 " and" mu ` =3do not satisfy (ii)
Hencethe givenlinesdo notintersecteach other .
29.

(d)/(dx)(e^((1)/(2)log(1+tan^(2)x))) is equal to

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`1/2sec^2x`
`sec^2x`
`secx.tanx`
`E^(1/2log(1+tan^2x)`

ANSWER :C
30.

If the vector equation of a plane passing through three points (1,0,z_1),(1,-1,1)," and "(4,-3,2) is barr.(-hati+3hatk)=2, then the value of z_1 is

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0
1
-1
3

Answer :B
31.

For each binary operation ** defined below, determine whether ** is commutative or associative on Q, define a**b=ab+1

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SOLUTION :`a**b=ab+1`
`b**a=ba+1=a**b``a,b in Q`
`THEREFORE **` is COMMUTATIVE
Since `(1**2)**3=(1xx2+1)**3`
`3**3=3xx3+1=10` and
`1**(2**3)=1**(2xx3+1)
`=1**7=1xx7+1=8`,
`(1**2)**3 ne 1**(2**3)`
`therefore **` is not associative
32.

Find the derivative of the function given by f(x)= sin x^(2)

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ANSWER :`2X COS X^(2)`
33.

Evaluate the following:""^(105)C_(0)=

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34.

Integrate the following functions e^x((1+sinx)/(1+cosx))

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SOLUTION :`INT e^x((1+sinx)/(1+cosx)) dx`
=`int e^x((1+2sin (x/2) COS(x/2)/(2cos^2 (x/2)) dx`
=`int e^x(1/2 sec^2 (x/2) + TAN (x/2)) dx`
=`e^x tan(x/2)+c, F(x) = tan x/2`
`f^.(x) = 1/2 sec^2 x/2`
35.

If a curve is .............

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SOLUTION :`(dx)/(dy)= - ((dx)/(DT))/((dy)/(dt))=(12 t^(2))/(12 t^(3))=1/t`
`(d^(2)x)/(dy^(2))=d/(dy)((dx)/(dy))=d/(dt)(1/t).(dt)/(dy)=(-1)/t^(2). 1/(12 t^(3))=(-1)/(12 t^(5))`
so `((-1)/(12 t^(5)))/((1/t)^(N))` is constant `implies n=5`
36.

Integrate the following functions. int(sqrtx)/(sqrt(a^(3)-x^(3)))dx

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ANSWER :`:. I=(2)/(3)SIN^(-1) (SQRT((x^(3))/(a^(3))))+C`
37.

Evaluate the following integrals inte^(x)(tan^(-1)x+(1)/(1+x^(2)))dx

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ANSWER :`E^(X)TAN^(-1)x+C`
38.

| overset(to)(a) | = 3, | overset(to)(b) | = sqrt(2)//3 and | overset(to)(a) xx overset(to)(b) | =1 . find the angle between overset(to)(a) and overset(to)(b)

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Answer :`= (PI)/(4)` or `(3PI)/( 4)` (any ONE VALUE)
39.

Consider f: {1,2,3} to {a,b,c} and g: {a,b,c} to {apple, ball, cat} defined as f (1) =a, f (2) =b, f (3)=c, g (a) = apple, g (b) =ball and g (c )= cat. Show that f, g and gof are invertible. Find out f ^(-1) , g ^(-1) and ("gof")^(-1) and show that ("gof") ^(-1) =f ^(-1) og ^(-1).

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ANSWER :`I _(Z)`
40.

If x^(2)- y^(2) + 4x-6y + k is resolvable into two linear factors, then k =

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-1
4
6
-5

Answer :D
41.

We have three solid bodies of same material A rightarrow a solid cube of edge length 'r' Brightarrow a solid sphere of radius 'r' and C rightarrow a solid hemisphere of radius 'r' In coloumnI certain situation related to these bodies are given Match the appropriate outcome indicated in column-II {:(,"Column-I",,"Column-II"),("(A)",underset("300k Then rate of fall of temperature with time")"All 3 bodies are heated to some temperature of 350k and kept in a room at",,"(P)for C is highest" "(Q)for B is highest"),("(B)",underset("C is kept with base on ground height of centre of mass from ground")"All 3 bodies are kept on level ground",,"(R)for C is lowest"),("(C)",underset("for cube and hemisphere is perpendicular to the fase and base respectively Moment of inertia")"All 3 bodies are rotated about an axis passing through their repective centre of mass the axis",,"(S) for one of the body is half of another body"):}

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SOLUTION :
42.

The value of the integral int_(0)^(n pi +1) (| cosx|+|sin x|) dx is

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`N`
`2n+SIN t + COST `
`cos t`
`sin t - cos t + 4N +1`

ANSWER :D
43.

If 3A =[(1,2,2),(2,1,-2),(x,2,y)] and A'A =I then x+y is equal to

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`-3`
`-2`
`-1`
0

Answer :A
44.

A : If cos (x-y) =3 cos ( x+y) " then " cot x - cot y=2 R : If (a)/(b)=(c)/(d) " then " (a+b)/(a-b)=(c+d)/(c-d)

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A is TRUE , R is true and R is correct EXPLANATION of A
A is true , R is TRUEAND R is not correct explanation of A
A is true , R is false
A is false , R is true

ANSWER :D
45.

If f(x) = cos^(2)x + cos^(2) 2x + cos^(2) 3x, then the number of values of x in [0, 2pi] for which f(x) = 1 is

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4
6
8
10

Answer :D
46.

Evalute the following integrals int x " tan"^(-1) (x^(2))dx

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ANSWER :`(x^(2))/(2) tan^(-1) (x^(2)) - (1)/(4) LOG (1 +x^(4)) ` +c
47.

If therootsof theequation x^4 - 10x^3 +50 x^2- 130 x+ 169= 0 areof theforma +- ibandb +- iathen(a,b)=

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`(3,2)`
`(2,1)`
`(-3,2)`
`(-3,-2)`

ANSWER :A
48.

Statement 1: in aDelta ABC ifa lt b lt cand r inradius andr_(1), r_(2), r_(3)are the exradii opposite to angle r gt r_(1) gt r_(2) gt r_(3)respectively thenStatement 2: For ,Delta ABC r_(1)r_(2) + r_(2) r_(3) + r_(3)r_(1) = (r_(1)r_(2)r_(3))/(r )

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If STATEMENT -1 is TRUE, statement –II is true, statement –II is a correct explanation for statement-I
If statement –I is true, statement –II is true, statement –II is not a correct explanation for statement –I
If statement –I is true, statement –II is FALSE
If statement –I is false, statement –II is true

Answer :D
49.

Coefficient of x^(n) in(e^(5x)+e^(x))/(e^(2x)) is .....

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`1/(N!) (3^(n) +1)`
`(3^n+5^n)/(n!)`
`(3^n+(-1)^n)/(n!)`
`1/(n!)`

ANSWER :C
50.

Draw the graph of f(x) " maximum " {2 sin x, 1 - cos x}, x in (0, pi). Also find the range of g(x) " min " {2 sin x, 1 - cos x}, x in (0, pi)

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Solution :Let us first DRAW graphs of `g_(1)(x) = 2 sin x` and `g_(2)(x) = 1 - cos x`
`g_(1)(0) = g_(1)(pi) = 0, g_(1)(pi//2) = 2`
`g_(2)(x) = sin x gt 0, AA x in (0, pi)`
So `g_(2)' (x)` is increasing.
`g_(2)(0) = 0, g_(2)(pi//2) = 1, g_(2)(pi) = 2`
Graph of functions are as shown in the FOLLOWING figure.

Curves y = 2 sin x and y = 1 - cos x intersect when
`4 sin^(2)x = (1 - cos x)^(2)`
`rArr` `4(1 + cos x) = (1 - cos x)`
`rArr` `4 + 4 cos x = 1 - cos x`
`rArr` `cos x = -3//5`
`rArr` `x = cos^(-1) (-3//5)`
`THEREFORE` `f(x) = {{:(2sinx",", 0 LT x lt pi - "cos"^(-1)(3)/(5)),(1- cos x",", pi - "cos"^(-1)(3)/(5) lt x lt pi):}`
Also the range of `g(x) = min {2 sin x, 1-cosx}` is `[0,1 - cos cos^(-1)(-(3)/(5))] -=[1, 8//5].`