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.

int (dx)/(tan x + cot x + sec x + cosec x) =

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`(1)/(2) (sin X - cos x + x) +c`
`(1)/(2) (sin x - cos x - tan x + COT x) + c`
`(1)/(2) (sin x- cos x-x) + c`
`(1)/(2) (sin x+ cos x - tan x - cot x) + c`

ANSWER :C
2.

Integrate the following functions : (x)/(1-cosx)

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ANSWER :`-xcot""(X)/(2)+2log|sin""(x)/(2)|+C`
3.

Differentiate the following w.r.t. x: log (log x), x gt 1

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ANSWER :`(1)/(X LOG x), x GT 1`
4.

Integrate the following : int2dx

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SOLUTION :`int2dx`=2x+C
5.

Differentiate sin^(2)x w.r.t e^(cos x)

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ANSWER :`-(2 COS X)/(E^(cos x))`
6.

The values of theta in (0,(pi)/(2)) satisfying

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`|(1+sin^(2)THETA,cos^(2)theta,4sin4theta),(sin^(2)theta,1+cos^(2)theta,4sin4theta),(sin^(2)theta,cos^(2)theta,1+4sin4theta)|=0`, are
`(7pi)/(24)`
`(5pi)/(24)`
`(13pi)/(24)`

ANSWER :A
7.

Let veca,vecb,vecc be the three vectors such thatveca.(vecb+vecc)+vecb.(vecc+veca)+vecc.(veca+vecb)=0 and |veca|=1,|vecb|=4,|vecc|=8, then |veca+vecb+vecc| equals :

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13
81
9
5

Answer :B
8.

Let overset(n)underset(r=1)Sigma overset(r )underset(j=1)Sigma overset(j)underset(k=1)Sigma 1=364, then n =

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ANSWER :12
9.

int_(pi)^(10pi) |sin x| dx=

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18
16
14
0

Answer :A
10.

If alpha, beta , gamma are the roots of the equation x^(3)+4x+1=0, then (alpha+beta)^(-1)+(beta+gamma)^(-1)+(gamma+alpha)^(-1) is equal to

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2
3
4
5

Answer :C
11.

Ifz = cos 6^(@) + isin 6^(@), " then " underset(n = 1) overset(20)sum (z^(2n-1))=

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0
`-1`
`(-3)/(4 sin 6^(@))`
`(3)/(4 sin 6^(@))`

Answer :D
12.

The tangent and normal to the ellipse x^2+4y^2=4 at a point (theta)on its meets the major axis in Q and R respectively. If 0ltthetaltx/2and QR=2 , then show that theta=cos^-1(2/3) .

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ANSWER :`THETA =cos^-1(2/3)`
13.

Find the number of ways to post 5 letters in 6 post boxes such that atleast two letters are posted in the same box.

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ANSWER :`6^5-""^6P_5`
14.

Assertion (A) : (1)/(5)+(1)/(3.5^(3))+(1)/(5.5^(5))+(1)/(7.5^(7))+…(1)/(2)log((3)/(2)) Reason (R ) : If |x| lt 1 then log_(e )((1+x)/(1-x))=2(x+(x^(3))/(3)+(x^(5))/(5)+…)

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

Answer :A
15.

Evalute the following integrals int tan^(5) xdx

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ANSWER :`(1)/(4) tan^(4) x - (1)/(2) tan^(2)` x + LOG |sec x | + C
16.

A relation R is form set A to B , and a relation S is from set B to C . Then relation SOR is from ........

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SET C to A
Set A to C
Does not EXIST
NONE of these

Solution :N/A
17.

If the area bounded by f(x) = sqrt(1 + x^(2) (x gt 0) the line y = x,y axis and y = - x + a (a > - 1) is k, then area bounded by the graph of f^(-1) (x), the line y = x between the lines y = - x + 1 and y = - x + a is

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`(4 K - 1)/(4)`
`(2k - 1)/(2)`
k
none of these

Answer :A-q, B-r, C-p, D-p
18.

If the matrix [{:(0,-1,3x),(1,y,-5),(-6,5,0):}] is skew- symmetric, then

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`x=-2,y=0`
`x=2,y=0`
`x=-2,y=1`
`x=2,y=-2`

ANSWER :B
19.

If the inequality (m-2)x^(2) + 8x + m + 4 gt 0 is satisfied for all x in R, then the least integral value of m is:

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ANSWER :5
20.

Find X, if Y=[(3,2),(1,4)] and 2X+Y=[(1,0),(-3,2)]

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ANSWER :`X=[(-1,-1),(-2,-1)]`
21.

{ xcos ((y)/(x)) + y sin ((y)/(x))} y dx = { y sin ((y)/(x)) - x cos ((y)/(x))}x dy

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ANSWER :`XY COS |(y)/(X)| = C`
22.

If C is arbitrary constant then inte^(sin^(-1)x)((lnx)/(sqrt(1-x^(2)))+1/x)dx is equal to

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`e^(SIN^(-1)xcosx)+C`
`-esin^(-1)x.ln(1/x)+C`
`(e^(sin^(-1)x))/x+C`
`e^(sin^(-1)x)/(sin^(-1)x)+C`

Solution :`inte^(sin-1)x((lnx)/(sqrt(1-x^(2)))+1/x)dx`
PUT `x=sin theta impliesdx=cos theta d theta`
`inte^(theta)((ln sin theta)/(cos theta)+1/(sin theta))cos theta d theta`
`=inte^(theta)(ln sin theta+cot theta)d theta=e^(0).ln(sin theta)+c`
`=e^(sin^(-1)x) lnx+c=-e^(sin^(-1)In(1/x)+C`
23.

[sqrt2(cos56^(@)15+isin56^(@)15')]^(8)

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1
i
16
16i

Answer :D
24.

Two balls of mass m_1 and m_2 (m_1 gt m_2) are thrown from the same point on the ground with same speed at angles theta_1 and theta_2(theta_1 gt theta_2, theta_1+theta_2=90^@ and theta_1 ne 0) fromhorizontal respectively. If R_1 and R_2 ae range, T_1 and T_2 are time of flight, H_1 and H_2 are maximum height then choose the INCORRECT option.

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`T_1 GT T_2`
`H_1 gt H_2`
`R_1 gt R_2`
`R_1 = R_2`

25.

sin A ( cot A +3( 3 cot A + 1) -1 " cosec " A -10 cos A =

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0
`1`
`-1`
`SQRT(2)`

ANSWER :A
26.

Find the area of the smaller part of the circle x^(2) + y^(2) = a^(2) cut off by the line x=a/sqrt2.

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ANSWER :`a^(2)/2 (pi/2-1)`
27.

Unit vectors vec(a),vec(b),vec(c ) are coplanar. A unit vector vec(d) is perpendicular to them. If (vec(a)xxvec(b))xx(vec(c )xxvec(d))=(1)/(6)i-(1)/(3)hat(j)+(1)/(3)hat(k) and the angle between vec(a) and vec(b) is 30^(@), then vec(c ) is/are :

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`PM(1)/(3)(-HAT(i)-2hat(j)+2hat(k))`
`(1)/(3)(2hat(i)+hat(j)-hat(k))`
`pm(1)/(3)(-hat(i)+2hat(j)-2hat(k))`
`(1)/(3)(-2hat(i)-2hat(j)+ hat(k))`

Solution :`vec(d)=pm((vec(a) XX vec(b)))/(|vec(a) xx vec(b)|)`
`THEREFORE" "(vec(a)xxvec(b).vec(d))vec(c )-(vec(a)xxvec(b).vec(c ))vec(d)=(1)/(6)hat(i)-(1)/(3)hat(j)+(1)/(3)hat(k)impliespm(1)/(2).vec(c )=(1)/(6)(hat(i)-2hat(j)+2hat(k))`
28.

Consider the points A(-2, -3) and B(1,6). i. Find the equation of the line passing through A and B. ii. Find the equation of the line passing through (2, 1) and perpendicular to AB iii. Find the foot of the above perpendicular to AB.

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ANSWER :i. -3x+y-3=0, II. x+3y-5=0, iii. `((-2)/(5), (9)/(5))`
29.

If a, b and c are perpendicular to b+c, c+a and a+b respectively and if |a+b|=6, |b+c|=8 and |c+a|=10, then |a+b+c| is equal to

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`5sqrt(2)`
`50`
`10sqrt(2)`
10

Solution :Given, `|a+b|=6`
`RARR""|a|^2+|b|^2+2a*b=36"…(i)"`
Similariy,`|b|^2+|c|^2+2b*c=64"…(ii)"`
and`|c|^2+|a|^2+2c*a=100"…(iii)"`
On adding Eqs. (i), (ii) and (iii), we GET
`2[|a|^2+|b|^2+|c|^2+(a*b+b*c+c*a)]=200`
`rArr""|a|^2+|b|^2+|c|^2=100"...(IV)"[because a*b+b*c+c*a=0]`
Now, `|a+b+c|^2=|a|^2+|b|^2+|c|^2+2(a*b+b*c+b*a=0)`
`rArr""|a+b+c|^2=100"[from EQ.(iv)]"`
`rArr""|a+b+c|=10`
30.

Show that the homogenous system of equations x - 2y + z = 0, x + y - z = 0, 3 x + 6y - 5z = 0has a non-trivial solution. Also find the solution

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Answer :` X = (K)/(3) , y = (2 k)/( 3), z = k` where k is an ARBITRARY constant.
31.

If cosalpha+cosbeta+cosgamma=0=sin alpha+sinbeta+singamma then cos^2alpha+cos^2beta+cos^2gamma=

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0
1
`COS2(alpha+beta+gamma)`
-1

Answer :A
32.

If the equation has no real root, then lamda lies in the interval

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`(-oo,0)`
`(-oo,6)`
`(6,oo)`
`(0,oo)`

Solution :If equation has no REAL roots, then (1) must have both roots negative for which
`(-b)/(2a)lt0implieslamdalt0""(5)`
`f(0)gt0or9gt0`
`:.lamdain(-oo,6)""["form"(2),(3),(5)]`
ALSO for no real roots we can have `Dlt0`
`implieslamda^(2)-36lt0implieslamdain(-6,6)`
HENCE, `lamdain(-oo,6)`
33.

Consider the triangle formed by the lines y+3x+2=0, 3y-2x-5=0, 4y+x-14=0 Match the following lists:

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SOLUTION :(a)

(b) Clearly, POINT `(0, alpha)` lies on y-axis.
So, `5//3 lt alpha lt 7//2`
(C)

(d)
34.

int_(0)^(pi//4)(sinx + cos x)/(7+9 sin 2x) dx =

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`(log 3)/(4)`
`(log 3)/(36)`
`(log 3)/(12)`
`(log 7)/(24)`

ANSWER :D
35.

Verify mean value theorem, if f(x) = x^(2) - 4x in the interval [1, 4].

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ANSWER :`C = (5)/(2)`
36.

A straight line L intersects perpendicularly both the lines : (x+2)/(2)=(y+6)/(3)=(z-34)/(-10) and (x+6)/(4)=(y-7)/(-3)=(z-7)/(-2), then the square of perpendicular distance of origin from L is

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ANSWER :5
37.

What is the vital capacity of our lungs ?

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IRV + TV
TLC - ERV
IRV + ERV
TLC - RV

Answer :A
38.

The non-zero vectors vec(a),vec(b),vec(c) are related by vec(a)=8vec(b)andvec(c)=-7vec(b). The angle betweenis vec(a)andvec(c) is

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

ANSWER :D
39.

Match the following : Let f be a function defined on {(m,n) : m and n are positive integers }Satisfying (i) f(m,m+1) = 1/3for all m (ii) f(m,n) = f (m,k) +f (k,n)-2f (k,n) for all such that m lt k lt n {:(,P,Q,R,S),((A),1,2,3,4),((B),4,3,1,2),((C ),3,2,4,1),((D),2,1,4,3):}

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ANSWER :(D )
40.

A chess game between two grandmasters X and Y is won by whoever first wins a total of two games. X's chances of winning or loosing any perticular game are a, b and c, respectively. The games are independent and a+b+c=1. The probability that X wins the match after (n+1)th game (nge1), is

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`na^2b^(n-1)`
`na^2b^(n-2)(B+(n-1)C)`
`na^2bc^(n-1)`
`NAB^(n-1)(b+nc)`

ANSWER :(b)
41.

Show that the lines 5x+3y-9=0,2x+y=0,x+3y=0 and x+4y+2=0 taken in order form a cyclic quadrilateral.

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ANSWER :we GET the EQUATION of CIRCLE.
42.

x dy - y dx = sqrt(x^(2) + y^(2)) dx

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ANSWER :`y + SQRT(X^(2) + y^(2)) = CX^(2)`
43.

If A is a square matrix of order 3 such that |A|=13, then |adj A| is equal to

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39
196
169
190

Answer :C
44.

Let vec(a)=hati+4hatj+2hatk,vec(b)=3hati-2hatj+7hatk and vec( c )=2hati-hatj+4hatk. Find a vector vec(d) which is perpendicular to both vec(a) and vec(b), and vec( c ).vec(d)=15.

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ANSWER :`=(1)/(3)(160hati-5hatj-70hatk)`
45.

int_(0)^(1) x^(3//2) sqrt(1-x) dx is equal to

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`pi/6`
`pi/9`
`pi/12`
`pi/16`

ANSWER :D
46.

Derive the reduction formula for int tan^(n) xdx.

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ANSWER :`I_(N)=(TAN^(n-1)X)/(n-1)-I_(n-1)`
47.

On putting (y)/(x)=v the differential equation (dy)/(dx)(2xy-y^(2))/(2xy-x^(2)) is transfored to

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`X(2v-1)DX=3v(v-1)dx`
`x(2v-1)dv=3v(1-v)dx`
`x(1-2v)dv=(v^(2)-2v)dx`
`(1-2v)dv=(v^(2)-2v)dx`

SOLUTION :PUTTING `y=vx` and `(dy)/(dx)=v+(dv)/(dx)`, given differetial equation reduces to
`v+x(dv)/(dx)=(2v-v^(2))/(2v-1)rArr3v(1-v)dx=x(2v-1)dv`
48.

A steel plant is capable of producing x tonnes per day of a law-grade steel and y tonnes per day of a hight-grade steel, where y=(40-5x)/(10-x). If the fixed market price of low-grade steel is half that of high-grade steel, then what should be optimal productions in law-grade steel and high-grade steel in order to have maximum receipts.

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ANSWER :`10-2sqrt(5) and 5-sqrt(5)`
49.

Solve the following differential equations (i) (dy)/(dx) - y tan x = e^(x)sec x (ii) (dy)/(dx) + y tan x = sin x

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Answer :(i) `y COS X = E^(x) + C`
(ii) y SEC x = log sec x + c
50.

Find two positive numbers x and y, such that x+y=64 and x^(3)+y^(3) is minimum.

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ANSWER :32, 32