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.

A question paper is divided into 3 sections A, B, C containing 3,4,5 questions respectively. Find the number of ways of attempting 6 questions choosing atleast one from each section.

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ANSWER :`""^(12)C_(6)-""^(7)C_(6)-""^(9)C_(6)=805`
2.

Evaluate the following integrals (v) int_(0)^(1)sin^(-1)x dx

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ANSWER :`(pi-2)/(2)`
3.

Roots of a quadratic equation x^(2)+5x+3=0 are 4cos^(2)alpha+a, and 4sin^(2)alpha+a. Another quadratic equation is given as x^(2)+px+q=0 where p, q in N and p, q in [1,10]. If roots of second quadratic equation are real then the probability that they are 4cos^(4)alpha + b and 4sin^(4)alpha + b is

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`(1)/(16)`
`(3)/(32)`
`(1)/(32)`
`(5)/(100)`

Answer :A
4.

Find the value of sin^(-1)((5pi)/(4))

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ANSWER :`(-PI)/(4)`
5.

int_(0)^(ln 2) Sin h 2x dx=

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`9/8`
`9/16`
`2ln 2-1`
`E^(2ln2)-1`

ANSWER :B
6.

Let z = x + iy, where x and y are integers. The area of the rectangle whose vertices are the roots of the equation zz^(3)+zbarz^(3) = 350 is

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32
40
48
80

Answer :C
7.

Verify Rolle's theorem for the following functions: f(x)= x^(3) -6x^(2) + 11x-6, x in [2, 3]

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ANSWER :`c=2 + (1)/(SQRT3)`
8.

If A and B are two matrices of the same order , then (AB) =A'B.

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ANSWER :FALSE
9.

Translate "If there is a will, there is a way" propositions into symbolic form, stating the prime components

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SOLUTION :LET p :There is a will, Q :There is a way.
`:.` The given STATEMENT is `prarr q`.
10.

Find the number of ways of permuting the letters of the word PICTURE so that no two vowels come together

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ANSWER :1440
11.

The range of the function , f (x) = tan^(-1) ((1+x)/(1 - x)) - tan^(-1) xis

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`{pi//4}`
`{-(pi//4),3pi//4}`
`{pi//4, - (3pi//4)}`
`{3 pi//4}`

ANSWER :C
12.

The set points on the axis of the parabola 2 ((x-1) ^(2) + (y-1) ^(2)) = (x + y) ^(2), from which 3 distinct nomals can be drawn to the parabola, is the set of points (h,k) tying on the axis of the parabola such that

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`H GT 3`
`h gt 3//2`
`k gt 3//2`
`k gt 3`

ANSWER :A::B::C::D
13.

If alpha is a root of x^(7)=1 and alpha ne 1, then alpha^(101)+alpha^(102)+......+alpha^(205) is :

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`0`
`104`
`-104`
`1`

ANSWER :A
14.

Which of the following are true: I : int_(0)^(4) sqrt(x^(2)-4x +4)dx=4 II : int_(0)^(2) sqrt(x^(2)-4x+4)dx=2 III : int_(2)^(4) sqrt(x^(2)-4x+4)dx=2

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Only I, II
Only II, III
Both I and II
Only III

Answer :D
15.

Solve the following equations : tan^(-1)(x/y)-"tan"^(-1)(x-y)/(x+y) is equal to

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`(PI)/2`
`(pi)/3`
`(pi)/4`
`(3pi)/4`

ANSWER :C
16.

If A-{a,b,c,d) mention the type of relations on A given below, which of them are equivalence relations? {(a, a),(b,b), (c,c), (d, d)}

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Solution :Reflexive, symmetric as WELL as TRANSITIVE .Hence it is an equivalence RELATION.
17.

Find the number of all 6-digit natural numbers such that the sum of their digits is 10 and each of the digits 0,1,2,3 occurs at least once in them.

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ANSWER :490
18.

If A-{a,b,c,d) mention the type of relations on A given below, which of them are equivalence relations? {(a, a),(b,b)}

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SOLUTION :SYMMETRIC and TRANSITIVE but not REFLEXIVE.
19.

If a, b, c are non-coplanar vectors and lambda is a real number, then [lambda(A+b)lambda^(2)b lambdac]=[a(b+c)b] for

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exactly TWO VALUES of `lambda`
exactly THREE values of `lambda`
no volue of `lambda`
exactly one value of `lambda`

SOLUTION :Given , `[lambda(a+b) lambda^(2)b lambdac]= [a(b+c)b]`
`|{:(lambda(a_(1)+b_(1)),lambda(a_(2)+b_(2)),lambda(a_(3) + b_(3))),(lambda^(2)b_(1),lambda^(2)b_(2),lambda^(2)b_(3)),(lambdac_(1),lambdac_(2),lambdac_(3)):}|=|{:(a_(1),b_(1)+c_(1),b_(1)),(a_(2),b_(2)+c_(2) ,b_(2)),(a_(3),b_(3)+c_(3),b_(3)):}| = |{:(a_(1),a_(2),a_(3)),(b_(1)+c_(1),b_(2)+c_(2),b_(3)+c_(3)),(b_(1),b_(2),b_(3)):}|`
`RARR lambda^(4)|{:(a_(1),a_(2),a_(3)),(b_(1),b_(2),b_(3)),(c_(1),c_(2),c_(3)):}|= - |{:(a_(1),a_(2),a_(3)),(b_(1),b_(2),b_(3)),(c_(1),c_(2),c_(3)):}|`
`rArr lambda^(4) = - 1`
So, no value of `lambda` exists.
20.

Identify the function from the above graph

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`tan^-1x`
`sin^-1x`
`cos^-1x`
`cosec^-1x`

ANSWER :B
21.

Let S,T ,Ube three non voidsetsand f: S rarrTg: T rarr U so thatgof : S rarrUis surjective then

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G and f are both surjective
g is surjective,f MAY not be so
f i s surjective, g may not be so
f and g both may not be surjective

Answer :B
22.

If the events A and B are mutually exclusive events such that P(A) = (1)/(3)(3x+1) and P(B) = (1)/(4) (1-x) , then the set of possible values of x lies in the interval

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[0,1]
`[(1)/(3),(2)/(9)]`
`[-(1)/(3),(5)/(9)]`
`[-(7)/(9),(4)/(9)]`

Answer :C
23.

Show that (i) sin^(-1)(2xsqrt(1-x^(2)))=2sin^(-1)x,-1/(sqrt(2))lexle1/(sqrt(2)) (ii) sin^(-1)(2xsqrt(1-x^(2)))=2cos^(-1)x,1/(sqrt(2))lexle1

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ANSWER :(i) `2sin^(-1)X` (II) `2COS^(-1)x`
24.

Find the set of values of p for which line 2px-4y+2pi-9=0 intersect the curve y=cos^(-1)at three distinct points.

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Solution :We have curve `y =f(x)=cos^(-1)(2x-1)`
and line 2px-4y+2pi-p=0
Domain of y =`f(x)=cos^(-1)(2x-1) is [0,1)`
`f(0)=cos^(-1)=pi and f(1)=cos^(-1)=0`
Graph of the function =f(x) is as shown in the following figure.

CLEARLY curve has point of inflection at `(1//2,pi//2)`
Examining the line , we find that it PASSES through `(1//2,pi//2)`

This line must INTERSECT the curve atthree distinct points.
Now `(dy)/(DX)=(-2)/sqrt(1-(2x-1))^(2)=(-1)/sqrt(x-x^(2))=-(x-x^(2))^(-1//2)`
`therefore ((dy)/(dx))_(x=0.5)=-2`
=slope of tangent to the curve at `(1//2,pi//2)`
It can be verified that that points `(0,pi)` and `(1//2,pi//2)and (1,0)` are collinear
slope of line joining these points is `(pi-(pi)/(2))/(0-(1)/(2))=-pi`
Hence given line intersect the curve at three distinct point if its slope is less than '-2' but more than or equal, to `-pi`
`therefore (p)/(2)in[(-pi,-2) rarr p in [-2pi,-4)`
25.

The solution set of the constraints x+2y ge 11, 3x+4y le 30, 2x+5y le 30, x ge 0, y ge 0 includes the point.

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(2, 3)
(3, 2)
(3, 4)
(4, 3)

ANSWER :C
26.

Find adjoint of each of the matrices{:[( 1,2),( 3,4)]:}

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ANSWER :` {:( 4,-2),( -3,1):}`
27.

Repeated roots : If equation f(x) = 0, where f(x) is a polyno- mial function, has roots alpha,alpha,beta,… or alpha root is repreated root, then f(x) = 0 is equivalent to (x-alpha)^(2)(x-beta)…=0, from which we can conclude that f(x)=0 or 2(x-alpha)[(x-beta)...]+(x-alpha)^(2)[(x-beta)...]'=0 or (x-alpha) [2 {(x-beta)...}+(x-alpha){(x-beta)...}']=0 has root alpha. Thus, if alpha root occurs twice in the, equation, then it is common in equations f(x) = 0 and f'(x) = 0. Similarly, if alpha root occurs thrice in equation, then it is common in the equations f(x)=0, f'(x)=0, and f'''(x)=0. If a_(1)x^(3)+b_(1)x^(2)+c_(1)x+d_(1)=0 and a_(2)x^(3)+b_(2)x^(2)+c_(2)x+d_(2)=0 have a pair of repeated roots common, then |{:(3a_(1),2b_(1),c_(1)),(3a_(2),2b_(2),c_(2)),(a_(2)b_(1)-a_(1)b_(2),c_(1)a_(2)-c_(2)a_(1),d_(1)a_(2)-d_(2)a_(1)):}|=

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0
1
-1
2

Solution :`"Let "f(x)=a_(1)x^(3)+b_(1)x^(2)+c_(1)x+d_(1)=0" has ROOTS "alpha, alpha,beta.`
`"Then "g(x)=a_(2)x^(3)+b_(2)x^(2)+c_(2)x+d_(2)=0" MUST have roots "alpha,alpha, gamma.` Then
`a_(1)alpha^(3)+b_(1)alpha^(2)+c_(1)alpha+d_(1)=0"(1)"`
`"and "a_(2)alpha^(3)+b_(2)alpha^(2)+c_(2)alpha+d_(2)=0"(2)"`
`alpha" is alos a root of equations "f'(x)=3a_(1)x^(2)+2b_(1)x+c_(1)=0 and `
`g'(x)=3a_(2)x^(2)+2b_(2)x+c_(2)=0.` Then
`3a_(1)alpha^(2)+2b_(1)alpha+c_(1)=0"(3)"`
`"and "3a_(2)alpha^(2)+2b_(2)alpha+c_(2)=0"(4)"`
`"Also, from "a_(2)(1)-a_(1)(2),"we have"`
`(a_(2)b_(1)-a_(1)b_(2))alpha^(2)+(c_(1)a_(2)-c_(2)a_(1))alpha+d_(1)a_(2)-d_(2)a_(1)=0"(5)"`
Eliminating `alpha" from "(3),(4), and (5)` we have
`|{:(3a_(1),2b_(1),c_(1)),(3a_(2),2b_(2),c_(2)),(a_(2)b_(1)-a_(1)b_(2),c_(1)a_(2)-c_(2)a_(1),d_(1)a_(2)-d_(2)a_(1)):}|=0.`
28.

Repeated roots : If equation f(x) = 0, where f(x) is a polyno- mial function, has roots alpha,alpha,beta,… or alpha root is repreated root, then f(x) = 0 is equivalent to (x-alpha)^(2)(x-beta)…=0, from which we can conclude that f(x)=0 or 2(x-alpha)[(x-beta)...]+(x-alpha)^(2)[(x-beta)...]'=0 or (x-alpha) [2 {(x-beta)...}+(x-alpha){(x-beta)...}']=0 has root alpha. Thus, if alpha root occurs twice in the, equation, then it is common in equations f(x) = 0 and f'(x) = 0. Similarly, if alpha root occurs thrice in equation, then it is common in the equations f(x)=0, f'(x)=0, and f'''(x)=0. If x-c is a factor of order m of the polynomial f(x) of degree n (1ltmltn), then x=c is a root of the polynomial [where f^(r)(x) represent rth derivative of f(x) w.r.t. x]

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`F^(m)(x)`
`f^(m-1)(x)`
`f^(n)(x)`
NONE of these

Solution :From the GIVEN information, we have `f(x)=(x-c)^(m)g(x),` where
g(x) is polynomial of degree n-m.
Then x=c is common root for the equations `f(x)=0,f^(1)(x)=0, f^(2)(x)=0,…,f^(m-1)(x)=0` where f'(x) represent rth DERIVATIVE of f(x) w.r.t. x,.
29.

If log(1+x)-(2x)/(2+x) is increasing, then

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`0 LT X ltinfty`
`-infty ltx lt 0`
`-infty lt x lt infty`
`-1 lt x lt 2`

Answer :A
30.

If sqrt(x+y)-sqrt(x-y)=c," then "(d^(2)y)/(dx^(2))

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`(1)/(y)((DY)/(DX))^(2)`
`(-c^(4))/(4y^(2))`
`y((dy)/(dx))^(2)`
`(-c^(2))/(4y^(3))`

Answer :B
31.

Prove by mathematical induction that n^(5)and n have the same unit digit for any natural numbern.

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Solution :We have to prove that `n^(5) - n` is divisible by 10.
For `n = 1, 1^(5) - 1 = 0` is divisible by 10.
Also, `n = 2 , 2^(5) - 2 = 30` is divisible by 10.
Thus, `P(1)` and `P(2)` are true.
`K^(5) - k = 10m"........"(1)`
Now, `(k + 1)^(5) - (k +1)`
`= k^(5) + 5K^(4) + 10k^(3) + 10 k^(2) + 5 k + 1 -k - 1`
`= (k^(5) - k) + 5 k(k^(3) + 1) + 10 k^(3) + 10 k^(2)`
`= 10 m + 10 k^(3) + 10 k^(2) + 5k(k^(3) + 1)` [Using (1)]
Clearly, `k(k^(3)+1)` is EVEN for `k in N`.
Thus, `P(k+1)` is true WHENEVER`P(k)` is true,
So, by the principleof mathematical induction,`P(n)` is true for any natural number n.
32.

Integrate the following functions : int(sec^(2)(logx))/(x)dx

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ANSWER :`TAN(LOGX)+C`
33.

Which of the followingstatements is/are correct with respect to surface phenomenon ?

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POTASSIUM ferrocyanide can cause greater coagulation in a basic dye as compared to `Na_(2)HPO_(3)`.
A starch aqua-sol can act as a protective colloid for `FE(OH)_(3)` sol.
The slope of the Freundlich Isotherm (log `(x)/(m)` vs log p) keeps on changing for a long range of pressure and is constant over a limited range of pressure.
On mixing `AgNO_(3)` with LARGE amount of KI and subjecting the colloidal state to electrophoresis, coagulation is OBTAINED at cathode.

Solution :(A) `K_(4)[Fe(CN)_(6)]rarr4K^(+)[Fe(CN0_(6)]^(-4)`
`Na_(2)HPO_(3)rarr2Na^(+)+HPO_(3)^(2-)`
higher negative charge over`[Fe(CN)_(6)]^(4-)` so it can cause more coagulation in a basic dye.
(B) Starch aqua-sol is a lyophilic sol so it can be used as protective colloid.
(C) Freundlichadsorptionisotherm fails at high pressure
34.

If the straight line joining the origin and the points of intersection of y=mx+1 and x^2+y^2=1be perpendicular to each other , then find the value of m.

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35.

Shwo that the difference of the squares of the tangents to two coplanar circles from any point P in the plane of the circles varies as the perpendicular from P on their radical axis. Also, prove that the locus of a point such that the difference of the squares of the tangents from it to two given circles is constant is a line parallel to their radical axis.

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ANSWER :a LINE which is PARALLEL to EQ. (III).
36.

intcos^5xsin^3xdx

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SOLUTION :`intcos^5xsin^3xdx`
=`intcos^5x(1-cos^2x)sinxdx`
[PUT cosx=t Then sinxdx=-DT]
=`intt^5(1-t^2).(-dt)=INT(t^7-t^5)dt`
=`1/8t^8-1/6cos^6x+C`
37.

Evaluate int(1)/(2sin^(2)+3sinxcosx-2cos^(2)x)dx

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Answer :`(1)/(5)LOG|(2tanx-1)/(2(tanx+2))|+c`
38.

Find the asymptodes of the hyperbola 2x^(2)+5xy+2y^(2)-11x-7y-4=0

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ANSWER :2x+y-1=0, x+2y-5=0
39.

For the equation (e ^(-x))/(1+x)= lamda which of the following statement (s) is/are correct ?

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when `lamda in (0,oo)` EQUATION has 2 real and DISTINCT ROOTS
when `lamda in (-oo, -e ^(2))` equation has 2 real anddistinct roots
when `lamda in (0,oo)` equatio has 1 real root
when `lamda in (-e,0)` equation has no real root

Answer :B::C::D
40.

If the two adjacent sides of a parallelogram are given by hat(i)+2hat(j)+3hat(k) and -3hat(i)-2hat(j)+hat(k), then the lengths of the diagonals are

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`2, 6sqrt(5)`
`2sqrt(5), 6`
`2, 6`
`2, SQRT(5)`

ANSWER :B
41.

int_(2)^(3) (1)/(x^(2)-x) dx=

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`LN. (2)/(3)`
`ln . 4/3`
`ln. 8/3`
`ln. 1/4`

ANSWER :B
42.

Integrate the following functions tan^2 (2x-3)

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SOLUTION :`INT tan^292x-3) DX`
=`int (sec^2(2x-3)-1)dx`
=`tan(2x-3)2 - x+c`
43.

inte^x((2+sin2x)/(1+cos2x))dx

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SOLUTION :`I= inte^x((2+sin2x)/(1+cos2x))DX`
=`inte^x((2+2sinxcosx)/(2cos^2x))dx`
=`inte^x(sec^2x+tanx)dx`
=`inte^xsec^2xdx+inte^xtanxdx`
=`inte^xsec^2xdx+e^xtanx-inte^xsec^2xdx+c`
=`e^xtanx+c`
44.

Choose the correct answer Suppose that two cards are drawn at random from a deck of cards. Let X be the number of aces obtained. Then the value of E(X) is

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`(37)/(221)`
`(5)/(13)`
`(1)/(13)`
`(2)/(13)`

ANSWER :D
45.

The sides of an equilateral triangle are increasing at the rate of sqrt 3 cm/sec. find the rate at which the area of the triangle is increasing when the side is 4 cm long.

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Solution :Let x be the LENGTH of each SIDE of an equilateral TRIANGLE :
Given thatdx/dt =`SQRT 3` cm/sec. if A is the area of the triangle then
`A = sqrt 3/4 x^2 rArr dA/dt = sqrt 3/4 cdot 2x dx/dt = sqrt 3/2 x cdot dx/dt`
Now dA/dt](x=4) = sqrt 3/2 xx 4xx sqrt 3=6`
therefore Area of the triangle is INCREASING at the rate of 6 `cm^2/sec`.
46.

Is the function defined by f(x)= x^(2)- sin x+ 5 continuous at x= pi?

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ANSWER :`X= PI`
47.

For a moderately skewed distribution

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M.D.=Q.D.
S.D.=M.D.
Q.D.=2/3 `SIGMA`
M.D.=4/5 `sigma`

ANSWER :C::D
48.

Find the points on the curve x^(2) + y^2 – 2x – 3 = 0 at which the tangents are parallel to the x-axis.

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ANSWER :`(1, PM 2)`
49.

What is the probability that 6 is obtained on one of the dice in a throw of two dice, given that the sum is 7.

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ANSWER :`(1)/(3)`
50.

The solution of (dy)/(dx) = (xy)/(x^(2) + y^(2)) is

Answer»

`X = ce^((x^(2))/(y^(2)))`
`y = ce^((x^(2))/(y^(2)))`
`x = ce^((x^(2))/(2Y^(2)))`
`x = ce^((2x^(2))/(y^(2)))`

ANSWER :C