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.

Integrate the functions (e^(x))/((1+e^(x))(2+e^(x)))

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ANSWER :`LOG((1+e^(X))/(2+e^(x)))+C`
2.

Find the area enclosed by the parabola 4y = 3x^(2) and the line 2y = 3x + 12.

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ANSWER :27
3.

Show that the normal at any point theta to the curve x = a cos theta + a theta sin theta, y = a sin theta - a theta cos theta is at the constant distance from origin.

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ANSWER :(0, 0)
4.

intx.tan^(-1)xdx=......+c

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`(x^(2)+1)/(2)tan^(-1)x+(x)/(2)`
`(x^(2)+1)/(2)tan^(-1)x-(x)/(2)`
`(x+1)tan^(-1)x+x`
`(x+1)/(2)tan^(-1)x+(x)/(2)`

ANSWER :B
5.

If A={:[( 3,1),( -1,2) ]:}Show that A^(2) -5A +7I=O.Hence find A^(-1)

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ANSWER :`(1)/(7) {:[(2,-1),(1,3)]:}`
6.

If f (x) = (sin 4pi [ pi ^(2) x ])/( 7 + [x ] ^(2)), [.] denotes ghe greatest integer function, then f (x) is

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continuous `AAX, ` but f '(X) does not EXIST.
DISCONTINUOUS at some x.
f"(x) exist `Aax`
f"(x) exist but f"(x) does not exists for some values

ANSWER :C
7.

A number n is chosen at random from S = {1,2,3…….50}. Then correct order of their probabilities is

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<P>`P(A) LT P(B) lt P("C")`
`P(A) GT P(B) gt P("C")`
`P(B) lt P(A) lt P("C")`
`P(A) gt P("C")gt P(B)`

ANSWER :B
8.

Iff (2) =4 and f (2)=1 , " then "lim_(x to 2)(x f(2) - 2f(x))/(x-2)is equal to

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`-2`
1
2
3

Answer :C
9.

Using the properties of determinants, prove the following |{:(a^2,b^2,c^2),((a+1)^2,(b+1)^2,(c+1)^2),((a-1)^2,(a-1)^2,(c-1)^2):}|=4|{:(a^2,b^2,c^2),(a,b,c),(1,1,1):}|

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ANSWER :`4|{:(a^2,B^2,C^2),(a,b,c),(1,1,1):}|`
10.

Find minors and cofactors of the elements a_(11),a_(21) in the determinant Delta=|{:(a_(11),a_(12),a_(13)),(a_(21),a_(22),a_(23)),(a_(31),a_(32),a_(33)):}|

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ANSWER :MINOR : `a_(11)=M_(11)=a_(22)a_(33)-a_(23)-a_(23)a_(32)`
`a_(21)=M_(21)=a_(12)a_(33)-a_(13)a_(32)`
COFACTOR : `a_(11)=a_(22)a_(33)-a_(23)a_(32)`
`a_(21)=-a_(12)a_(33)+a_(13)a_(32)`
11.

If two circles (x+4)^(2)+y^(2)=1 and (x-4)^(2)+y^(2)=9 are touched extermally by a circle, then locus of centre of variable circle is

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`(x^(2))/(15)-(y^(2))/(1)=1`
`(x^(2))/(4)-(y^(2))/(12)=1`
`(x^(2))/(1)-(y^(2))/(15)=1`
`(x^(2))/(12)-(y^(2))/(4)=1`

Solution :
`CS=r+1`
`CS'=r+3`
`CS'-CS=2`
Locus of C is hyperbola with `(-4,0)` and `(4,0)` as foci,
Here, 2a=2, so a = 1.
Also, 2ae = 8, so ae = 4
`therefore""b^(2)=a^(2)(e^(2)-1)=15`
12.

Resolve (x^(2)+4x+7)/((x^(2)+x+1)^(2)) into partial fractions.

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ANSWER :`(1)/(X^(2)+x+1)+(3x+6)/((x^(2)+x+1)^(2))`
13.

int (cos x + x sin x )/(x (x + cos x ))dx =

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`log |("x + COS x")/(x )| + c `
log lx (x + cos x )l + c
`log |(x)/(x+ cos x )| + c `
log lx (COSX + x sinx)+ c

ANSWER :C
14.

Find the latus rectum of the parabola 2x^2+3y=0

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15.

If f: R to R defined as f(x) = (2x-7)/( 4) is an invertible function, write f^(-1) (x).

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Answer :`F^(-1) (x) = (4 x+7)/( 2)`
16.

int [ log(log x) + (log x )^(-2) ]dx =

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`X { LOG (log x) - (1)/(log x ) } + C`
x log (log x) - `(1)/(" log x ")+ c`
log (log x )- `(x)/(log " x") + c`
x [ log (log - x) - log x ] + c

ANSWER :A
17.

Metal (M) crystallizes in a cubic unit cell with density 3.2 g/cc. Edge-length of the unit cell is 4.37Å picometre (pm) The nearestneighbour will be

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On the corners
On the BODY diagonal
On the FACE diagonal
On OPPOSITE face

Answer :C
18.

Metal (M) crystallizes in a cubic unit cell with density 3.2 g/cc. Edge-length of the unit cell is 4.37Å picometre (pm) The number of nearest neighbours of a Ca atom are

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4
6
8
12

Answer :D
19.

If the first and the n^("th")term of a G.P. are a and b, respectively, and if P is the product of n terms, prove that P^2 = (ab)^n.

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ANSWER :` = (AB)^(N)`
20.

If f : R to R is defined by f (x) =x ^(2) - 3x + 2, find f (f (x)).

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ANSWER :`X ^(4) - 6x ^(3) + 10 x ^(2) - 3X`
21.

If P (A) = 0.4,P (B | A)= 0.3 and P (B^c | A^c)=0.2. find P ( B | A^c)

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<P>

SOLUTION :`P(B|A^c)=(P(BcapA^c))/(P(A^C))=(P(B-A))/(1-P(A))`
`=(P(B)-P(A capB))/(1-P(A))=(0.6-0.12)/(1-0.4)=0.48/0.6=0.8=4/5`
22.

Find longest wavelength in Lyman series of hydrogen atom spectrum.

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1216Å
216Å
1016Å
116Å

Answer :A
23.

int_(0)^(pi//2) (1)/(1+e^(sqrt(2)sin(x-pi//4)))dx=

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0
`pi//2`
`pi//8`
`pi//4`

ANSWER :D
24.

Prove that underset(r = 0) overset (n)(sum) 3^(r) ""^(n)C_(r) = 4^(n)

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ANSWER :`4^(N)`
25.

(p rArr q) rarr [(r vv p) rArr (r vv q)] is

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a TAUTOLOGY
a contradiction
a tautology and a contradiction
neither a tautology nor a contradiction

Answer :B
26.

If (0, 1//2), (1//2, 1//2), (1//2, 0) are the midpoints of the sides of a triangle, then incentre of the triangle is

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`((1)/(SQRT(2)), (1)/(sqrt(2)))`
`(1+(1)/(sqrt(2)), 1+(1)/(sqrt(2)))`
`(1-(1)/(sqrt(2)), 1-(1)/(sqrt(2)))`
`(1+(1)/(sqrt(2)),1-(1)/(sqrt(2)))`

ANSWER :C
27.

Molarity and Molality of a solution of an liquid (mol. Wt. = 50) in aqueous solution is 9 and 10 respectively. What is the density of solution ?

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1 g/cc
0.95 g/cc
1.05 g/cc
1.35 g/cc

Answer :A
28.

The saving of an employee equals Income minus Expenditure. If their Incomes ratio is 1 : 2 : 3 and their Expenses rato is 3 : 2 : 1, then what is the order of the employees, A , B and C in the increasing order of the size of their saving?

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A GT B gt C
A gt C gt B
B gt A gt C
C gt B gt A

Answer :D
29.

Find the equation of the parabola whose axis is parallel to X-axis and which passes through these points. (-2,1),(1,2), and (-1,3)

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ANSWER :`7Y^(2)-3y+6x-16=0`
30.

What is the sum of the squares of the roots of the equation x^(2)-7[x] + 5 = 0 ? (Here [x] denotes the greatest integer less than or equal to x. For example [3.4] = 3 and [-2.3] =-3).

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ANSWER :69
31.

The point on the curve x^2=2y which is nearest to the point (0,5) is --

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`(2sqrt2,4)`
`(2sqrt2,0)`
(0,0)
(2,2)

ANSWER :A
32.

Determine the sine of the angle between the vectors 5hati-3hatj, 3hati-2hatk

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Solution :
`|vecaxxvecb| = sqrt(36+100+81) = sqrt(217)`
`|veca| = sqrt(25+9) = sqrt(34)`
`|vecb| = sqrt(9+4) = sqrt(13)`
If `theta` is the ANGLE between `veca` and `vecb` then
`sintheta = |vecaxxvecb|/(|veca||vecb| = sqrt(217)/(sqrt(34) sqrt(13)) = sqrt((217)/442).
33.

Estimate the integral int_(0)^(1) sqrt(1 + x^(4)) dx using (a) themean-valuetheoremfor a definite integral, (b) the result of the preceding problem, (c) the inequalitysqrt(1 + x^(4)) lt 1 + (x^(4))/(2) (d)the Schwarz-Bunyakovaskyinequality(see Problem 6.3.6)

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ANSWER :(a) `1.414`
(B) 1.207
(C)1 . 1
(d)1 . 095
34.

Integrate the function (6x+7)/(sqrt((x-5)(x-4)))

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ANSWER :`|X-(9)/(2)+sqrt(x^(2)-9x+20)|+c_(2)`
35.

Solve as directed: 2x + 3 gt 15 in integers, in natural numbers.

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SOLUTION :2x + 3 `GT` 15
`rArr 2x + 3-3 `gt` 15-3
`rArr 2x gt 12`
`(2x)/2 gt (12)/2`
`x gt 6`
If x `in` Z then the solution set isS = {x:x `in` Z and x `gt` 6}
= {7,8,9………}
If x `in` then the solution set is S = {x:x `in` N and x `gt` 6}
{7,8,9.......}
36.

Find the value of 1/x for the following values of x : (a)[-5 , -1](b)(3,6)(c )(-2 , 3)(d )(-oo , -2]( e)[-3,4]

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Solution :(a) `2 lt X lt 5`
` rArr1/2 gt 1/xgt1/5`
`RARR 1/(x)in(1/5,1/2)`
(b) `-5 le x lt -1`
`rArr-1/5ge 1/x gt-1`
`rArr1/(x)in(-1,-1/5]`
(c) `x gt3 or 3 lt x lt oo`
`x le -2 or - oo lt x le-2`
`rArr0 gt1/xge-1/2`
`rArr1/x""in[-1/2,0)`
(e ) `x in [-3 4]or -3 le x le 4`
Now for `1/x `to get defined ,we must have `-3 le x lt 0 ` or `0 lt x le 4`
`rArr -1/3 ge 1/xgt -ooor 1/4 le 1/x""lt oo`
`rArr1/x""in(-oo,1/3]CUP[1/4,oo)`
37.

(2x^(4)+3x^(2)+1)/((x^(2)+1)^(4))=(A)/((x^(2)+1))+(B)/((x^(2)+1^(2)))+(C)/((x^(2)+1)^(3))+(D)/((x^(2)+1)^(4)) then Match the following. {:("List - I","List - II"),("1) A","(a) 2"),("2) B","(b) 1"),("3) C","(c) -1"),("4) D","(d) 0"), (,"(e) 1/2"):}

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d, a, C, d
c, a, E, d
B, a, e, d
c, b, e, d

Answer :A
38.

If the variance of first n natural numbers is 2 and the variance of first m odd natural numbers is 40, then m+n =

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Solution :Variance of first N natural numbers is `(n^2-1)/12=2 RARR n^2=25 rArr n=5`
variance of first m ODD natural numbers is
`2^2 ((m^2-1))/12=40 rArr (m^2-1)/12=10`
`rArr m^2-1 =120 rArr m^2=121 rArr` m=11
39.

If A = [(2,-1,3),(-4,5,1)]and B = [(2,3),(4,-2),(1,5)]then :

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only AB is DEFINED
only BA is defined
AB and BA both are defined
AB and BA both are not defined .

ANSWER :C
40.

The sum of the series 1+(1^2+2^2)/(2!)+(1^(2)+2^(2)+3^(2))/(3!)+(1^(2)+2^(2)+3^(2)+4^2)/(4!)+.. Is

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3e
`(17)/(6)E`
`(31)/(6)e`
`(13)/(6)e`

Answer :C
41.

If (x^(2)+x+1)/(x^(2)+2x+1)=A+B/(x+1)+C/(x+1)^(2) then A - B =

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4C
2C
3C
`4C+1`

ANSWER :B
42.

If hat(i)+hat(j)-hat(k), 2hat(i)+3hat(j), 3hat(i)+5hat(j)-2hat(k) and -hat(j)+hat(k) are the position vectors of vertices of a quadrilateral, then it is a

Answer»

parallelogram
trapezium
rectangle
square

Answer :B
43.

Find the locus of the point whose polars with respect to the circles x^(2) + y^(2) -4x -4y -8=0 and x^(2) + y^(2) -2x + 6y -2= 0are mutuallyperpendicular.

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ANSWER :` X^(2) + y^(2) -3X + y -4=0 `
44.

If the circles of same radii and with centres (1, 3), (9, 11) cut orthogonally then radius is

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2
4
8
16

Answer :C
45.

The value ofint_(-(1)/(2))^((1)/(2)){[x]+log((1+x)/(1-x))}dx is equal to -

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0
1
`-(1)/(2)`
`2"log"(1)/(2)`

ANSWER :C
46.

If abs(z-2)lesqrt2, then the maximum value of abs(3+i(z-1)) is

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`SQRT2`
`2SQRT2`
`2+sqrt2`
`3+sqrt2`

ANSWER :B
47.

If f (x) = sin (2x ^(2) -2 [x]) for 0 lt x lt 1, then f ' ((sqrtpi)/(2))=

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`- (SQRTX)/(2)`
`-sqrt2`
0
`(sqrtx)/(2)`

Answer :C
48.

If the line joining the points hati+hatjand3hati+hatj-hatk meets the plane that passes through the point 2hati+4hatj and parallel to the vectors 3hati+5hatkand3hati-hatk at, P, then the position vector of the point P is

Answer»

`-27hati+hatj+14hatk`
`29hati+hatj-14hatk`
`-14hati+89hatj+3hatk`
`2hati+5hatj-7hatk`

ANSWER :B
49.

For all real value of k, the polar of the point (2k,k-4) with respect to x^2+y^2-4x-6y+1=0 passes through the point

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(1,1)
(1,-1)
(-3,1)
(3,1)

ANSWER :D
50.

The most general value of theta which satisfies both the equations tan theta =-1 and cos theta =1/sqrt2 is

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`NPI+(7pi)/4`
`2npi+(7pi)/4`
`npi+(-1)(7pi)/4`
`(7npi)/4`

ANSWER :B