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.

If sin beta=sin(2alpha+beta) then find the value of (cotalpha+cot(alpha+beta))(cot beta-5cot(2alpha+beta))?

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Solution :`((COS ALPHA)/(sinalpha)+(cos(alpha+BETA))/(sin (alpha+beta)))((cosbeta)/(sinbeta)-(5 cos(2alpha+beta))/(sin(2alpha+beta)))`
`(sin(2alpha+beta))/(sinalpha(alpha+beta))((cosbeta)/(sinbeta)-(5 cos(2alpha+beta))/(5 sinbeta))`
`(5 sin beta)/(sin alpha.sin(alpha+beta))((cosbeta-cos(2alpha+beta))/(sin beta))`
`(10 (sin alpha.sin(alpha+beta)))/(sinalpha.sin(alpha+beta))=10 `
2.

Three non-zero real numbers form a AP and the squares of these numbers taken in same order form a GP. If the possible common ratios are (2pm sqrt(k)) where k in N, then the value of [k)/(8)-(8)/(k)) is (where [] denites the greatestinteger function).

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SOLUTION :Let number of AP are `(a-d),a,(a+d)`.
According to the question, `(a-d)^(2),a^(2),(a+d)^(2)` are in GP.
`:.(a^(2))^(2)=(a-d)^(2)(a+d)^(2)`
`implies a^(4)=(a^(2)-d^(2))^(2)`
`implies a^(4)=a^(4)+d^(4)-2a^(2)d^(2)`
`implies a^(2)(a^(2)-2D^(2))=0`
`implies ane0," So "a^(2)=2d^(2)`
`implies a=pm sqrt(2d)"" "......(i)"`
Let common ratio of GP is r.
`:.r^(2)=((a+d)^(2))/((a-d)^(2))`
`implies r^(2)=(a^(2)+d^(2)+2ad)/(a^(2)+d^(2)-2ad)`
`implies r^(2)=(2d^(2)+d^(2)+2sqrt(d^(2)))/(2d^(2)+d^(2)-2sqrt(d^(2)))`
`"" [" from EQ. (i) for"a= sqrt(2)d]`
`implies r^(2)=((3+2sqrt(2))d^(2))/((3-2sqrt(2))d^(2))`
`implies r^(2)=((3+2sqrt(2))(3+2sqrt(2)))/(9-8)`
`implies r^(2)=(3+2sqrt(2))^(2)`
`implies r^(2)=(3+sqrt(8))^(2)`
`:. r=pm(3+sqrt(8))`
`impliesr=3+sqrt(8) "" [:." ris positive "]`
Similarly, for `a=-sqrt(2)d,` we get
`r=pm(3-sqrt(8))`
`implies r=(3-sqrt(8)) "" [:. " r is positive "]`
COMPARE r with `3pmsqrt(K)`, we get
`k=8`
`[(k)/(8)-(8)/(k)]=[(8)/(8)-(8)/(8)]`
`= [1-1]=[0]=0`.
3.

Find the volume of the parallelepiped with segments AB, AC and AD as concurrent edges, where the position vectors of A, B, C, D are hat(i)+hat(j)+hat(k),2hat(i)-hat(j)+3hat(k),3hat(i)-2hat(j)-2hat(k)and3hat(i)+3hat(j)+4hat(k) respectively.

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27 CU. units
41 cu. units
10 cu. units
52 cu. units

Answer :B
4.

Find least positive integer x, satisfying 276x+128=4 (mod 7).

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Solution :Now 128 -= mod 7
Now `176 x+128 -=4 "mod" 7`
`implies 176x -=(4-2)"mod" 7`
`implies 176 x -=2 "mod" 7`
`176 XX x=2 "mod" 7`,
` "But" 276 -= 3 "mod" 7,`
`"THUS" x=3`.
5.

If ui=axi+b and vi =cyi+d then

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cov (u,v)
e(u,v) =e(x,y)
`e(u,v) =(AC)/(|ac|) e(x,y)`
None of these

Answer :A::C
6.

If the foot of perpendicular from origin to the plane is (1,2,3) then the equation of the plane is............

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`(x)/(1) + (y)/(2) + (Z)/(3) = 1`
`x + 2y + 3Z =1`
`x+2y + 3z = 6`
`x + 2y + 3z = 14`

Answer :D
7.

int(1)/(x)[sqrt[x-1)/(sqrt(x+1])]dx=

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`Cos H^(-1)x-Sec^(-1)x+c`
`Cosh^(-1)x+Sec^(-1)x+c`
`SINH^(-1) x- Sec^(-1) x+c`
`SIN h^(-1)x-"COSEC"^(-1)x+c`

Answer :A
8.

If the 4 points made by intersection of lines 2x-y+1=0, x-2y+3=0 with the coordinate axes are concylic then centre of circle is

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(7/4,5/4)
(7/4,-5/4)
(-7/4,5/4)
(-7/4,-5/4)

ANSWER :C
9.

Find the mean deviation of the first three odd natural numbersfrom their mean.

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ANSWER :`4//3`
10.

int (1)/((x^(2)+9)sqrt(x^(2)-9))dx=

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Answer :`(1)/(18sqrt(2))log|(xsqrt(2)+SQRT(X^(2)-9))/(xsqrt(2)-sqrt(x^(2)-9))|+C`
11.

y= f(mu), where f(mu) = (3)/(2mu^(2) + 5mu -3) and mu=(1)/(x+2). Find the points of discontinuity of y.

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ANSWER :`x=0, -2, -(7)/(3)`
12.

lim_(xto 8)(sqrt(1 + sqrt(1 + x -2))/(x -8)is equal to

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`3/2`
`1/4`
`1/24`
`1/12`

ANSWER :C
13.

The area of the region bounded by the curves y=x^(2)andy=(2)/(1+x^(2)) is

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ANSWER :`PI-(2)/(3)`
14.

Prove that : Find the sum of the infinite series 1+(2)/(3).(1)/(2)+(2.5)/(3.6)((1)/(2))^(2)+(2.5.8)/(3.6.9)((1)/(2))^(3)+......oo

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`ROOT(3)(3)`
`root(4)(4)`
`root(4)(8)`
`root(3)(4)`

ANSWER :D
15.

Find the sum of all 4 digited numbers that can be formed using the digits 0,2,4,7,8 without repetition.

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ANSWER :545958
16.

Evaluate the following integrals (iii) int_(- pi/2)^(pi/2) sin |2x|dx

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ANSWER :2
17.

An urn contains 5 red and 5 black balls. A ball is drawn at random, its colour is noted and is returned to the urn. Moreover, 2 additional balls of the colour drawn are put in the urn and then a ball is drawn at random. The probability that the second ball drawn is red will be

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ANSWER :`(1)/(2)`
18.

Compute P(X=k) for the binominal distribution, B(n,p) where n=10, p=1/5, k=4

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ANSWER :`210(1/5)^(4)(4/5)^(6)`
19.

Evaluate the following integrals int(cosx)/(3cosx+4sinx)dx

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ANSWER :`(4)/(25)log|3cosx+4sinx|+(3)/(25)x+c`
20.

Find the area of the region bounded by the curve y^(2) = 4x and the line x = 3.

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ANSWER :`8sqrt3`
21.

If a_(1), a_(2), a_(3), ………, a_(n)….. are in G.P., then the determinant Delta =|(""loga_(n)" "loga_(n + 1)" "log_(n + 2)""),(""loga_(n + 3)" "loga_(n + 4)" "log_(n + 5)""),(""loga_(n + 6)" "loga_(n + 7)" "log_(n + 8)"")| is equal to

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0
1
2
4

Answer :A
22.

If a=(2, 1, -1), b=(1, -1, 0), c=(5, -1, 1), then unit vector parallel to a + b - c but in opposite direction is

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`(1)/(3)(2hati-hatj+2hatk)`
`(1)/(2)(2hati-hatj+2hatk)`
`(1)/(3)(2hati-hatj-2hatk)`
None of these

Solution :Let a = (2, 1, -1), B = (1, -1, 0) and C = (5, -1, 1)
Then, `a+b-c=(2+1-5)hati+(1-1+1)hati+(-1+0-1)hatk`
`=-(2hati-hatj+2hatk)`
`because` Unit VECTOR of `(a+b-c)=-((2hati-hatj+2hatk))/(3)`
`therefore` Required unit vector of `(a+b-c)=((2hati-hatj+2hatk))/(3)`
23.

If points A(bara) = 10i + 3j . B (barb) = 12i - 5j and C (barc) = ai + 11j are collinear, then a =

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`-8`
4
8
12

Answer :D
24.

Solve[y(1-x tan x)+x^(2) cos x] dx -xdy=0

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ANSWER :`y= X^(2)cosx+cxcosx`
25.

Findthe quotientand theremainderwhenx^4 -6x^3 +3x^2 + 26- 24isdividedbyx-4

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ANSWER :`x^3 -2x^2 -5X +6` remainder=0
26.

int(sec^2x.cosec^2x)dx

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SOLUTION :`INT(sec^2x.cosec^2x)DX`
=`INT1/(sin^2xcos^2x)dx`
=`int(sin^2x+cos^2x)/(sin^2xcos^2x)`
=`int(sec^2+cosec^2)dx`
=tanx-cotx+C
27.

Find (dy)/(dx),if y = log(log x).

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ANSWER :`(1)/(X LOG x), x GT 1`
28.

Find the matrix X such that , X[{:(5,-7),(-2,3):}]=[{:(-16,-6),(7,2):}].

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ANSWER :`[{:(-60,-142),(25,59):}]`
29.

Acceleration -position graph for a particle moving along x-axis is given below. At origin velocity of particle is 5 m/s then velocity of particle at x=6 m is :

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5 m/s
7 m/s
3 m/s
10 m/s

30.

Let A=[{:(2,4),(3,2):}],B=[{:(1,3),(-2,5):}],C=[{:(-2,5),(3,4):}] Find each of the following : (i) A+B ,(i) A-B, (iii) 3A-C, (iv) AB, (v)BA

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ANSWER :(i) `=[{:(3,7),(1,7):}]`
(ii) `=[{:(1,1),(5,-3):}]`
(iii) `=[{:(8,7),(6,2):}]`
(iv) `=[{:(-6,26),(-1,19):}]`
(V) `=[{:(11,10),(11,2):}]`
31.

If A=[{:(1,0,0),(0,1,0),(0,0,1):}]then A^(2)+2A= ……….

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4A
3A
2A
A

Answer :B
32.

Find all points of discontinuityof f, where f is defined by f(x)={{:(x^(10)-1," if "x le1),(x^(2)," if "x gt 1):}

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ANSWER :F is DISCONTINUOUS at x=1.
33.

Using elementary row transformations , find the inverse of [{:(2,0,-1),(5,1,0),(0,1,3):}]

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ANSWER :`thereforeA^(-1)=[{:(3,-1,1),(-15,6,-5),(5,-2,2):}]`
34.

Differentiate the functions with respect to x in Exerecises 1 to 8. sin (x^(2)+5)

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Answer :`2x cos (X^(2)+5)`
35.

If y = sin ^(2) alpha + cos ^(2) (alpha + beta) + 2 sin alpha sin betacos(alpha+beta) then (d^(3)y)/(da^(3))=?

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`sin^(3) (ALPHA +beta)/(COSALPHA)`
`sin ( alpha + beta)`
0
1

Answer :C
36.

Integrate the following functions : int(dx)/(sqrt(1-(4x+5)^(2)))

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ANSWER :`(1)/(4)SIN^(-1)(4x+5)+C`
37.

Find the area of the region bounded by y= |x|,y=0, x = -1 and x= 1

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ANSWER :1
38.

The internal centre of similitude of the two circles x^(2)+y^(2)+6x-2y+1=0, x^(2)+y^(2)-2x-6y+9=0 is

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ANSWER :(i) (2,6) (II) `(0,5/2)`
39.

If the normals at the points t_(1) and t_(2) on y^(2) = 4ax at the point t_(3) on the parabola, the t_(1)t_(2)=

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4
3
2
`2t_(3)`

ANSWER :C
40.

Find the values of each of the expression following : sin^(-1)("sin"(pi)/3)

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ANSWER :`(PI)/3`
41.

How many ordered pair of integers ( a,b) satisfy all the following inequalities a^(2) +b^(2) lt 16 , a^(2) +b^(2) lt 8 a,a^(2) +b^(2) lt 8b?

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ANSWER :6
42.

IFalpha, betabe theroots of6x^2-6x +1=0 then (1)/(2) (a+ ba+ calpha^2+ dalpha ^3)+(1)/(2)(a+ b beta + cbeta^2 +d beta ^3)=

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`a + beta+C+d`
` a + 2B + 3C + 4D `
`a+b//2+c//3 + d //4`
none

Answer :C
43.

{:(" "Lt),(n rarr oo):}1/n sum_(r=1)^(2n)(r)/(sqrt(n^(2)+r^(2)))=

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`1+sqrt(5)`
`1-sqrt(5)`
`sqrt(3)-1`
`sqrt(3)+1`

Answer :B
44.

Find the angle between the curves x^(2)-(y^(2))/(3)=a^(2)andax^(3)=c.

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ANSWER :`90^(@)`
45.

Solve that |{:(1+x,1-x,1-x),(1-x,1+x,1-x),(1-x,1-x,1+x):}|=0

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o OR 1
o OR -1
0 OR -3
0 OR 3

ANSWER :D
46.

Find the shortest distance between the lines(x-1)/(2)=(y-2)/(3)=(z-3)/(4) and (x-2)/(3)=(y-4)/(4)=(z-5)/(5)

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ANSWER :`(1)/(SQRT6)`
47.

Evalute the following integrals int (1)/(4 sin^(2) x + 3 sin" x cos x " +2 cos^(2)x)dx

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ANSWER :`(2)/(sqrt(23)) tan^(-1) ((8"tan x + 3")/(sqrt(23))) + C `
48.

The sum upto (2n+1) terms of the series a^(2)-(a+d)^(2)+(a+2d)^(2)-(a+3d)^(2)+… is

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`a^(2)+3ND^(2)`
`a^(2)+2nad+N(n-1)d^(2)`
`a^(2)+3nad+n(n-1)d^(2)`
`(a+nd)^(2)+n(n+1)d^(2)`

ANSWER :D
49.

In a bulb factory, three machines, A, B, C, manufacture 90%, 25% and 15% of the total production respectively. Of their respective outputs, 1 %, 2% and 1 % are defective. A bulb is drawn at random from the total product and it is found to be defective. Find the probability that it was manufactured by machine C.

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ANSWER :`2/25`
50.

Using the properties of determinants, prove the following |{:((x-2)^2,(x-1)^2,x^2),((x-1)^2,x^2,(x+1)^2),(x^2,(x+1)^2,(x+2)^2):}|=-8

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ANSWER :-8