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.

Evaluate the following (iii) int_(0)^(5)x[x]dx

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ANSWER :35
2.

For the binomial distribution (a + p)^(n) = ((1)/(2) + (1)/(2))^(10) if A = P (x = 3 ) , B = P (x = 6) , C = P (x = 9) then the ascending order of A , B , C is

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C , A , B
A , B , C
A , C , B
B , C , A

ANSWER :A
3.

Find the direction cosines of the unit vector perpendicular to the plane vecr.(6hati-3hatj-2hatk)+1=0 passing through the origin.

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ANSWER :`(-6)/(7),3/7,2/7`
4.

Evaluate: int _( 0 ) ^(pi) e ^(|cos x|)( 2 sin ((1)/(2)cos x )_+ 3 cos ((1)/(2)cos x ))sin x dx

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Answer :`(24)/(5) [ E cos ""1/2 + e SIN ""1/2 -1]`
5.

If 15 boys of different ages are distributed into 3 groups of 4,5, and 6 boys randomly then the probability that three youngest boys are in different groups is

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`24/91`
`71/91`
`67/91`
`20/91`

ANSWER :A
6.

If n is an integer then show that (1 + cos theta +i sin theta)^(n) + (1 + cos theta - i sin theta )^(n)= 2^(n+1) cos ^(n) ( theta//2) cos ((n theta)/2).

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7.

Leta = hati+ hatj+ hatkand letr beavariablevectorsuchthatr . "" hati, r."" hatj , r .""Kare positiveintegersifr.ale12thenthe numberof valuesofr is

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`""^(12)C_(9)-1`
`""^(12 )C_(3)`
`""^(12)C_(4)`
none

Answer :B
8.

If f (x) =|sin x-|cos x ||, then f '((7pi)/(6))=

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`(sqrt3+1)/(2)`
`(1-sqrt3)/(2)`
`(sqrt3-1)/(2)`
`(-1-sqrt3)/(2)`

ANSWER :C
9.

Solve the differential equation : (dy)/(dx) =1 + x^(2)+y^(2)+x^(2)y^(2) .

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ANSWER :`TAN^(-1)y =X+(x^(3))/(3)+c`
10.

Prove that :int_(0)^(1) (log x)/(sqrt(1-x^(2)))dx=-(pi)/(2)log 2

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11.

Evaluate the following determinants. [[1,2,3],[1,2,3],[3,4,5]]

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SOLUTION :`[[1,2,3],[1,2,3],[3,4,5]]=0 (becauseR_1=R_2)`
12.

(i) ifA=[{:(1,-4),(3,1):}]and b=[{:(1,0,5),(-2,4,3):}],then show that : (AB)'=B'A' implies(1)/(2)(A-A')=[{:(0,3//2,-4),(-3//2,0,7//2),(4,-7//2,0):}] Now A=(1)/(2)(A+A')+(1)/(2)(A-A') implies[{:(2,0,-4),(-3,1,5),(4,-2,3):}]=[{:(2,-3//2,0),(-3//2,1,3//2),(0,3//2,3):}]+[{:(0,3//2,-4),(-3//2,0,7//2),(4,-7//2,0):}](ii) if A=[{:(2,3),(0,1):}]and B=[{:(3,4),(2,1):}],then prove that : (AB)'=B'A'

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SOLUTION :N/a
13.

Show that the operation * on Z define by a* b =a+b+1 for all a,b in Z Satisfies (i) the closure property (ii) the associative law and (iii) the commutative law ltrbgt (iv) find the identity element inZ (v) what is the inverse iof an element a in Z ?

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Solution :(i) closure porperty
LET a `in` A ,b in Z then
a*b=a+b+1
Nowa `in` Z , b in Z `RARR` a+b in Z
`rarr` a+b +1 `in` Z
`therefore` * on Z satisfies the closure propety
(ii) Associative law
For all a,b,c `in` Z we have
(a*b)*c=(a+b+1)*c
=(a+b+1)+c+1
=a+b+c+2
a*(b*c)=a*(b+c+1)
=a+(b+c+1)+1
=a+b+c+2
`therefore` (a*b)*c=a*(b*c)
(iii) commutative law
For all a,b `in` Z we have
a*b=a+b+1 ltbrgeb+a+1 [`therefore` a+b+=b+1]
=b*a
(iv) Existence of identity element
Let e be the identity element in Z
Then a * e =a `rarr` a+e+1=a
`rarr` =-1
Thus -1 in Z is the identity element for *
(V) Existence of inverser
Let a in Z and let ISTS iverse e be b then
a*b=-1 `rarr` a+b+1=-1
`rarr` b =-(2+a)
clearly 2`in` Z a in Z `rarr` -(2+a) `in` Z
Thus each a in Z has -(2+a)in Z as its INVERSE
14.

Radius of the circle vec(r_(2))+vecr(2hati-2hatj-4hatk)-19=0. vecr.(hati-2hatj+2hatk)+8=0, is

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5
4
3
2

Answer :B
15.

Illustrate the use of all connectives and the modified 'not' in five separate examples of propositions

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Solution :Conjunction :HARI and Madhu are two friends. DISJUNCTION :Hari or Madhu STAND first in their CLASS.
Implication : If I will be the king , then I will you my queen.
Double Implication . I will love you If you will love me.
Negation. I don.tlike her.
16.

A particle performing S.H.M undergoes displacement of A//2 (where A = amplitude of S.H.M.) in one second. At t = 0 be the particle was located at either position or mean position. The time period of S.H.M. can be : (consider all possible cases)

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12s
2.4
6s
1.2s

Answer :A::B::C::D
17.

A survey shows that in a city that 63% of the citizens like tea where as 76% like coffee. If x% like both tea and coffee, then

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`x=39`
`x=63`
`39le x le 63`
`30 le x le 80`

ANSWER :C
18.

If omega is an imaginary cube root of unity, then the value of (2 - omega )(2 - omega^(2) ) + 2(3 - omega )(3 - omega^(2)) + .... .... + (n - 1)(n - omega)(n -omega^(2)) is

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`(N^(2))/4(n+1)^(2)-n`
`(n^(2))/4(n+1)^(2)+n`
`(n^(2))/4(n+1)^(2)`
`(n^(2))/4(n+1)^(2)-n`

ANSWER :A::D
19.

A plane pi makes intercepts 3 and 4respectivelyon z - axisand x- axis . If pi is parallel to y - axis , then its equation is

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`3x+4Z = 12`
`3Z + 4X = 12`
`3y + 4z = 12`
`3z +4y = 12`

ANSWER :A
20.

Find the values of each of the following : If "tan"^(-1)(x-1)/(x-2)+"tan"^(-1)(x+1)/(x+2)=(pi)/4, then find the value of x.

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ANSWER :`+-1/(SQRT(2))`
21.

When 9th termof AP is divided by its 2nd term then quotient is 5 and when 13th term is divided by 6th term then quotient is 2 and Remainder is 5 then find first term of AP.

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Solution :given `impliesT_(0)=5T_(2)` &` T_(13)=2T_(6)+5`
so `a+8d=5(a+d)` & `a+12d=2(a+5d)+5`
`impliesa=3`
22.

Differentiate(a^x-b^x)/x

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SOLUTION :`y=(a^X-b^x)/x`
`(DY)/(DX)=(d/dx(a^x-b^x)cdotx-(a^x-b^x)cdotd/(dx)(x))/x^2`
`((a^xlna-b^xlnb)x-(a^x-b^x))/x^2`
23.

Determine the truth of falsity of the If A is a proper subset of B and B is a subset of C Then A is a proper subset of C propositions with reasons.

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SOLUTION :If A is a proper subset of B and B is a subset of C, then A is a proper subset of C.It is TRUE, as
`X in A impliesx in B (:.A sub B)`and x in `B implies x in C(:.B sub C) x in A impliesx in C MEANS A sub C`.
24.

Differentiate 2sqrtcot(x^2) w.r.t.x

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SOLUTION :`d/dx(2sqrtcot(x^2))=2d/dx[sqrtcot(x^2)]=2XX1/(2sqrtcot(x^2))d/dx(COT(x^2))=1/sqrtcot(x^2)xx-cosec^2(x^2)=(-2xcosec^2(x^2))/(sqrtcot(x^2)`
25.

If theequationwhoserootsarep timestherootsofx^4 +2x^3 +46x^2 +8x+16 =0isareciprocalequationthen p=

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2
3
`+- 1/2`
`+-1/3`

ANSWER :C
26.

Find the equation of line passing through the given points using determinants (5,-1),(5,3)

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ANSWER :x=5
27.

Integrate the rational functions x/((x-1)^(2)(x+2))

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ANSWER :`(2)/(9) log|x-1|+(1)/(3)((x-1)^(-2+1))/(-1)-(2)/(9)log|x+2|+c`
28.

Constract the composition table/multiplication table for the binary operation * defined on {0,1,2,3,4}by a**b =axxb ("mod" =5). Find the identity element if any. Also find the inverse elements of 2 and 4.

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SOLUTION :`A ={0,1,2,3,4}`
`a**b =axx b "mod" 5`

As 3rd row is identical to the FIRST row we have 1 is the IDENTITY CLEARLY `2^(-1) =3 "and" 4^(-1) =4.`
29.

Match the following {:("I.","The approximate value of"(2*001)^4,"a",0*4983),("II".,"The approximate value of"(1*0002)^(3000),b,2.02),("III.","The approximate value of"sqrt(4*08),c,1*6),("IV.","The approximate value of" 1/(3sqrt(8*08)),d,16*032):}

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C,B,d,a
d,c,b,a
a,c,b,d
c,b,d,a

Answer :C
30.

y = cos^(-1)((2x)/(1+x^2)), -1 lt x lt 1.

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ANSWER :`(-2)/(1+x^(2))`
31.

A person observes the top of a tower from a point A on the ground. The elevation of the tower from this point is 60^(@). He moves 60 m in the direction perpendicular to the line joining A and base of the tower. The angle of elevation of the tower from this point is 45^(@). Then, the height of the tower (in meters) is

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`60sqrt(3/2)`
`60sqrt(2)`
`60sqrt(3)`
`60sqrt(2/3)`

ANSWER :A
32.

1+(1+5)/(2!) +(1+5+5^2)/(3!) + ......oo =

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`1/4 E(e^4 +1)`
`1/4 e(e^4 -1)`
`1/3 e(e^4 +1)`
`1/3 e(e^4 -1)`

ANSWER :B
33.

From the top of a tower 100 m heigh, the angles of depression of two objects 200 m apart on the horizontal plane and in a line passing through the foot of the tower and on the same side of the tower are 45^(@) - A and 45^(@) + A, then angle A is equal to

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`15^(@)`
`22.5^(@)`
`30^(@)`
`35^(@)`

ANSWER :B
34.

Find the derivative of the following functions 'ab initio', that is, using the definition.t(t-1)

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Solution :LET `y=t(t-1)=t^2-t`
Then
`dy/dt=lim_(DELTAT TO0)([(t+deltat)^2-(t-deltat)]-[t^2-t])/(deltat)`
`=lim_(deltat to0)(t^2+2tdeltat+deltat^2-t-deltat-t^2+t)/(deltat)`
`=lim_(deltat to0)[(2t-1)+deltat]=2t-1`
35.

Evaluate the integral (a)int_(-pi)^(pi) f(x) cos nx dx (b) int_(-pi)^(pi) f(x) sin nx dxf : (1) f(x) is an evenfunction ,(2) f(x) is an odd function.

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ANSWER :(1)if f (x)is an even function, then
`int_(-pi)^(pi) f(x) cos NX DX = 2 int_(0)^(pi) f(x) cos nx dx, and int_(-pi)^(pi) f(x) sin x dx = 0 `
(2)If f(x) is an odd function, then `int_(-pi)^(pi) f(x) cos nx dx = 0`, and`int_(-pi)^(pi)f(x) sin nx dx = 2 int_(0)^(pi) f(x)`sin n dx
36.

Find the product of the perpendiculars drawn from the point (x_1,y_1) on the lines ax^2+2hxy+by^2=0

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ANSWER :`=(|ax_1^2+2hx_1y_1+by_1^2|)/SQRT({(a-b)^2+4h^2})`
37.

Find dy/dx,x=a cos'theta',y=a sin theta.

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SOLUTION :`x=a cos theta,y=a SIN theta `
Then `DX/(d theta)=-a sin theta `
`DY/(d theta)=a cos theta fracdy/d theta`
`dy/dx=(dy/(d theta))/((dx)/(d theta))=(a COSTHETA)/(-a sin theta) =-cot theta`
38.

Write the following functions in the simplest form : tan^(-1)((cos x -sin x)/(cos x + sin x)), -pi/4 lt x lt (3pi)/4

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SOLUTION :`tan^(-1)((cos X - sin x)/(cos x + sin x)) = tan^(-1)((cos x(1-tanx))/ (cos x(1+tanx)))`

`tan^(-1)((1-tanx)/(1+tanx))= tan^(-1)tan(pi/4-x) = pi/4-x`
39.

If int_(-3)^(2) f(x)dx= 7/3 and int_(-3)^(9) f(x)dx= - 5/6 then int_(2)^(9) f(x)dx=

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`3/2`
`- 3/2`
`- 19/6`
`19/6`

ANSWER :C
40.

If Delta ABC, A' B' C' are such that B=B', A+A'=180^@, then aa'=

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`aa'+bb'`
bb'+cc'
aa'+cc'
None

ANSWER :B
41.

There are (n + 1) white and (n + 1) black balls, each set numbered 1 to n + 1. The number of ways in which the balls can be arranged in a row so that adjacent balls are of different colours, is

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(2N + 1)
2(2n)!
2[(N + 1)!]
`2[(n+1)!]^(2)`

ANSWER :D
42.

Which one of the following vectors of magnitude sqrt(51) makes equal angles with three vectors vec(a)=(hat(i)-2hat(j)+2hat(k))/(3), vec(b)=(-4hat(i)-3hat(k))/(5) and vec(c)=hat(j)?

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`5hat(i)-hat(j)-5hat(K)`
`5hat(i)+hat(j)+5hat(k)`
`-5hat(i)-hat(j)+5hat(k)`
`5hat(i)+5hat(j)-k`

Solution :Let `vec(p)=XHAT(i)+yhat(j)+zhat(k)` is a vector of magnitude `sqrt(51)`
`:.sqrt(x^(2)+y^(2)+z^(2))=sqrt(51)`
`rArr x^(2)+y^(2)+z^(2)=51 " " ...(i)`
Let `vec(p)` makes equal angle `theta` with and `vec(a), vec(B) and vec(c)`.
`:.vec(p).vec(a)=|vec(p)|.|vec(a)|cos theta`
`:. cos theta = (vec(p).vec(a))/(|vec(p)||vec(a)|)`
Similarly, `cos theta = (vec(p).vec(b))/(|vec(p)||vec(b)|)`
and `cos theta = (vec(p).vec(c))/(|vec(p)||vec(c)|)`
`:. (vec(p).vec(a))/(|vec(p)||vec(a)|)=(vec(p).vec(b))/(|vec(p)||vec(b)|)=(vec(p).vec(c))/(|vec(p)||vec(c)|)`
`rArr ((1)/(3)(x-2y+2z))/(sqrt(x^(2)+y^(2)+z^(2))(1)/(3)sqrt(1+4+4))=((1)/(5)(-4x-3z))/(sqrt(x^(2)+y^(2)+z^(2))(1)/(5)sqrt(16+9))=(y)/(sqrt(x^(2)+y^(2)+z^(2))sqrt(1))`
`rArr (x-2y+2z)/(3sqrt(x^(2)+y^(2)+z^(2)))=(-4x-3z)/(5sqrt(x^(2)+y^(2)+z^(2)))=(y)/(sqrt(x^(2)+y^(2)+z^(2)))`
`rArr (x-2y+2z)/(3)=(-4x-3z)/(5)=y`
`:. 5(x-2y+2z)=-3(4x+3z)=15Y`
`:. 5x-10y+10z=15y and -12x-9z=15y`
`rArr 5x-25y+10z=0 and -12x-15y-9z=0`
`rArr x-5y+2z=0 and 4x+5y+3z=0`
`x-5y+2z=0`
`4x+5y+3z=0`
`|(x,y,z),(1,-5,2),(4,5,3)|=(x)/(-15-10)=(y)/(8-3)=(z)/(5+20)`
`(x)/(-25)=(y)/(5)=(z)/(25)`
`(x)/(-5)=(y)/(1)=(z)/(5)=k`(let)
`:. x=-5k, y=k, z=5k`
Now, `x^(2)+y^(2)+z^(2)=51`
`:. (-5k)^(2)+k^(2)+(5k)^(2)=51`
`rArr 25k^(2)+k^(2)+25k^(2)=51`
`rArr 51k^(2)=51`
`:. k=pm1`
When, k=1, then `x=-5, y=1, z=5`
`and vec(p)=5hat(i)+hat(j)+5hat(k)`
when k=-1 , then x=5, y=-1, z=-5
`and vec(p)=5hat(i)-hat(j)-5hat(k)`
43.

Evalute the following integrals int (1)/(sqrt(5x - 6- x^(2)))dx

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ANSWER :`sin^(-1) (2X - 5)` + C
44.

If ""^(n)C_(3)=10, then n is

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45.

Ifalpha, beta are the roots of the equationx^(2) + x + 1 = 0 then prove thatalpha^(4) + beta^(4) + alpha^(-1) beta^(-1) = 0 .

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46.

If radii of two circles are 4 and 3 and distance between centres is sqrt37, then angle between the circles is

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`30^@`
`45^@`
`60^@`
`90^@`

ANSWER :C
47.

Find the sum of all five digited numbers that can be formed using the digits 1, 2, 3, 7, 9.

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ANSWER :5866608
48.

1+(1)/(3.2^(2))+(1)/(5.2^(4))+(1)/(7.2^(6))+....=

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1
`log_(e )2`
`log_(e )3`
`log_(e )4`

ANSWER :C
49.

If a + b + c = 0, then the equation 3ax^(2) + 2bx + c = 0 has, in the interval (0, 1)

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at leastone ROOT
atmost ONE root
no root
exactly one root

ANSWER :A
50.

In thegridshownbelow, eachsmallsquarehasa side lengthof 1 unit. Intheshadedregion , eachvertex lieson avertexof a small square. Whatis the area, in squareunits , of theshaded region ?

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35
25
24
19

Answer :D