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.

Write the simplest form of tan^(-1) [( 3 cos x - 4 sin x )/( 4 cos x + 3 sin x) ], if (3)/(4) tan x gt -1

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ANSWER :`TAN^(-1) (3//4) - X`
2.

If A(3,5), B(-5, - 4), C(7, 10) are the vertices of a parallelogram, taken in the order, then the co-ordinates of the fourth vertex are

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(10, 19)
(15, 10)
(19,10)
(15, 19)

ANSWER :D
3.

Let R be the region containing the point (x, y) on the X-Y plane, satisfying 2le|x+3y|+|x-y|le4. Then the area of this region is

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5 SQ. units
6 sq. units
7 sq. units
8 sq. units

Solution :The REGION is enclosed between two PARALLELOGRAMS of AREA `4xx2 and 2xx1`
The area `=8-2=6.`
4.

The point (3,1) is a point on a circle C with centre (2,3) and C is orthogonal to x^(2) + y^(2) = 8. The conjugate point of (3,1) w.r. tox^(2) + y^(2) = 8which lies on C is

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(5,1)
(5,4)
(1,5)
(0, + 2)

ANSWER :C
5.

If the volume of parallelopiped with coterminous edges 4hati+5hatj+hatk, - hatj+hatk and 3hati+9hatj+phatk is 34 cu units, then p is equal to

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4
`-13`
13
6

Solution :SINCE, volume of parallelopiped `=34`
`:. |(4,5,1),(0,-1,1),(3,9,p)|=34`
`IMPLIES 4(-p-9)-5(-3)+1(3)=34`
`implies -4p-36+15+3=34`
`implies 4p=-52`
`implies p=-13`
6.

Find adjoint of each of the matrices in Exercises 1 and 2 [{:(1,-1,2),(2,3,5),(-2,0,1):}]

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ANSWER :`[{:(3,1,-11),(-12,5,-1),(6,2,5):}]`
7.

Find the distance of the point (2,1,-1) is equidistant from the plane x-2y+2z+4z=9.

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ANSWER :`13/21sqrt(21)` UNITS
8.

Find the d.r. of the normal to the plane 4x + 3y - z + 6 = 0 and

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`LT -4, -3, 1 GT`
`lt 4, -3, -1 gt`
`lt 4, -3, -1 gt`
`lt 4, 3, -1 gt`

Answer :D
9.

If int(x+(cos^(-1)3x)^(2))/(sqrt(1-9x^(2)))dx=Psqrt(1-9x^(2))+Q(cos^(-1)3x)^(3)+c then

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`P=-(1)/(9)`
`Q=-(3)/(8)`
`P=(3)/(8)`
`Q=-(1)/(9)`

ANSWER :A::D
10.

Show that the foot of the perpendicular from focus to the tangent of the parabola y^(2)=4ax lies on the tangent at vertex.

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ANSWER :`rArrx_(1)=0`
11.

If the area of the triangle formed by the pair of lines 8x^(2) - 6xy + y^(2) =0 and the line 2x + 3y = a is 7 , then a is equal to

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`14`
`14 SQRT2`
`28 sqrt2`
`28`

ANSWER :D
12.

int_(-pi//2)^(pi//2) cos theta (1+sin theta)^(2) d theta=

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`(14)/(3)`
`(8)/(3)`
`(5)/(14)`
0

Answer :B
13.

The position vector of a point A is (4, 2, -3). If the distance of the point A from XY- plane is p_(1) and from Y - axis is p_(2) then p_(1)+p_(2)= ………….

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2
3
8
7

Answer :C
14.

int (log x )^(3) dx =

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`X [ (log x)^(3) - (log x)^(2) + (log x) - 6]` + c
`x [ (log x)^(3) + (log x )^(2) - (log x ) - 6 ]` + c
`x [ (log x)^(3) + (LOGX)^(2) + (logx) - 6] ` + c
`x[(log x)^(3) -3( log x)^(2) + 6 (log x)-6 ] + c `

ANSWER :D
15.

Find the are length of the cardioid rho= a (1 + cos varphi) (a gt 0, 0 le varphi le 2pi)

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ANSWER :8A
16.

Find the values of the following integrals (v) int_(0)^(pi/4) sec^(6)x dx

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ANSWER :`(28)/(15)`
17.

((1+isinpi/8+cospi/8)/(1-isinpi/8+cospi/8))^(8) equals

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`2^(8)`
0
`-1`
1

Answer :C
18.

If the radius of a sphere is measured as 9 m with an error of 0.03 m, then find the approximate error in calculating its surface area.

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ANSWER :`2.16 PI m^(3)`
19.

Coefficient of x^(n) in log_(e )(1+(x)/(2)) is

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`(1)/(N.2^(n))`
`((-1)^(n-1))/(n.2^(n))`
`((-1)^(n))/(n.2^(n))`
`((-1)^(n))/(2^(n))`

ANSWER :B
20.

Find the number of 4-digit numbers that can be formed using the digits 0, 1,2, 3, 4, 5 which are divisible by 6 when repetition of the digits is allowed

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ANSWER :180
21.

If f(x)=||x-1|+|x-3|-|2x-1||+||x-1|+|x-3|+|2x-1||, then

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`F(X)` is non-differentiable at `x=1`
`f(x)` is non differentiable at `x=3/2`
`f(x)` has minimum value is 2
`x=1` is POINT of local minima

Solution :`:'f(x)=2XX"max"{|x-1|+|x-3|,|2x-1|}`
`:.x=1, 3/2` point of non-differentiability and minimum value is 2
22.

The symmetric equation of lines 3x+2z-5=0 and x+y-2z-3=0 is

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`(x-1)/(5)=(y-4)/(7)=(z-0)/(1)`
`(x+1)/(5)=(y+4)/(7)=(z-0)/(1)`
`(x+1)/(-5)=(y+4)/(7)=(z-0)/(1)`
`(x-1)/(-5)=(y-4)/(7)=(z-0)/(1)`

Solution :Let a,b,c be the direction RATIOS of REQUIRED line.
`therefore 3a+2b+c=0`
and a+b-2c=0
`Rightarrow (a)/(-4-1)=(b)/(1+6)=(c)/(3-2)`
`Rightarrow (a)/(-5)=(b)/(7)=(c)/(1)`
In order to find on the required line, we put z=0 in the two given equations to obtain 3x+2y=5 and x+y=3.
On SOLVING these two equations, we get x=-1, y=4
`therefore` Coordintaes of POINT on required line are (-1,4,0)
Hence, required line is `(x+1)/(-5)=(y-4)/(7)=(z-0)/(1)`
23.

Probability that A speaks truth is 4/5. A coin tossed. A reports that a head appears. The probability that actually there was head is a)4/5 b)1/2 c)1/5 d)2/5

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ANSWER :A
24.

((cos3theta-isin3theta)^4)/((sin2theta+icos2theta)^5)=

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SOLUTION :-(sin2theta+icos2theta)
25.

Statement-1 :Delta_(f)H_(400K)^(@) is zero for O_(2)(g) Statement-2 : Delta_(f)H_(298K)^(@) is zero for O(g).

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STATEMENT-1 is TRUE, statement-2 is true and statement-2 is correct explanation for statement -2
Statement-1 is true, statement-2 is true and statement-2 is correct NOT explanation for statement -2
Statement-1 is true, statement-2 is FALSE
Statement-1 is false, statement-2 is true

Solution :( C) N/A
26.

Integrate the functions (cossqrtx)/(sqrtx)

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ANSWER :`2sinsqrtx+C`
27.

What is the diagonal of the rectangle shown?

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ANSWER :26
28.

Express in polar form (mod-Amplitude form) -sqrt7 + isqrt(21)

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ANSWER :B::C
29.

The unit vector in the direction of bar(x)=(-2,1,-2) is …………..

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`((2)/(3),-(1)/(3),(2)/(3))`
`(-(2)/(3),(1)/(3),-(2)/(3))`
`(-(2)/(9),(1)/(9),-(2)/(9))`
`((2)/(9),-(1)/(9),(2)/(9))`

ANSWER :B
30.

Differentiate the following w.r.t.x sin^-1(x^3)

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SOLUTION :`d/dx[sin^-1(x^3)]=1/(SQRT(1-(x^3)^2)d)d/dx(x^3)=(3x^2)/sqrt(1-x^6)`
31.

Let f(x) =(x -2) (x^(4) -4x^(3) + 6x^(2) - 4x +1) then value of local minimum of f is

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`-2//3`
`-(4//5)^(4)`
`-4^(4)//5^(5)`
`-(4//5)^(5)`

ANSWER :C
32.

The set of all solutions of the inequation x^(2) - 2x +5 le 0 in R is

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`R-(-infty, -5)`
`R- (5, infty)`
`phi`
`R-(-infty, -4)`

ANSWER :C
33.

Using the fact that 0 le f(x) le g(x) , c lt x lt d rArr int_(c)^(d) f(x) dx le int_(c)^(d) g(x) dx, we can conclude that int_(1)^(3) sqrt(3+x^3) lies in the interval

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`((1)/(2),3)`
`(2, SQRT(30) )`
`((3)/(2), 5)`
`(4, 2 sqrt(30) )`

ANSWER :D
34.

If int_(1)^(2) (dx)/( (x^(2) -2x + 4)^(3/2))=(k)/( k+5) then k is equal to

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`1`
`2`
`3`
`2`

ANSWER :A
35.

Find (dy)/(dx) in the following: y= tan^(-1) ((a cos x- b sin x)/(b cos x + a sin x))

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ANSWER :`-1`
36.

Differentiate tan^2x+sec^2x

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SOLUTION :`y=tan^2x+sec^2x`
`dy/dx=2tanxcdot d/dx(TANX)+2secxd/dx(SECX)`
`=2tanxcdot sec^2x+2sec^2xcdot tanx=4sec^2x tanx`
37.

If the normal at any point P on the ellipse x^2/a^2+y^2/b^2=1 meets the axes in G and g respectively. Find the ratio PG:Pg

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ANSWER :`b^2:a^2`
38.

Which of the following matrice is invertible? [[2,1,-2],[1,2,1],[3,6,4]]

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Solution :LET A=`[[2,1,-2],[1,2,1],[3,6,4]]`
`therefore ABSA =[[2,1,-2],[1,2,1],[3,6,4]]`
=`2[[2,1],[6,4]]-1[[1,1],[3,4]]-2[[1,2],[3,6]]`
=2(8-6)-(4-3)-2(6-6)
=4-1-0=`3 ne 0`
39.

A is a set containg n elements. A subset P of A is chosen at random and the set A is reconstructed by replacing the random. Fond the probability that Pcup Q contains exactoly r elements with1 le r le n.

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ANSWER :`((.^nC_r3')/(4^n))`
40.

If four positive integers are taken at random and multiplied together, then the probability that the last digit is 1, 3, 7 or 9 is

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`1/8`
`2/7`
`1/625`
`16/625`

ANSWER :D
41.

The set of point (x,y) satisfying x+y le 1 , -x-yle 1 lie in the region bounded by the two straight lines passing through the respective pair of points.

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`{(1,0) ,(0,1)} and {(-1,0) ,(0,-1)}`
`{(1,0) ,(1,1)} and {(-1,0) ,(0,-1)}`
`{(-1,0) ,(0,-1)} and {(1,0) ,(-1,1)}`
`{(1,0) ,(0,-1)} and {(-1,0) ,(0,1)}`

ANSWER :A
42.

A factory has three machines, X,Y and Z, producing 1000,2000 and 3000 bolts per day respectively. The machine X produces 1% defective bolts, Y produces 1.5% defective bolts and Z produces 2% defective bolts. At the end of the day, a bolt is drawn at randomand it is found to be defective. What is the probability that this defective bolt has been produced by the machine X?

Answer»

<P>

Solution :Total number of bolts produced in DAY
`=(1000+2000+3000)=6000`.
Let `E_1,E_2and E_3` b the events of drawing a bolt produced by MACHINES X, Y and Z respectively. Then,
`P(E)=1000/6000=1/6,P(E_2)=2000/6000=1/3andP(E_3)=3000/6000=1/2`.
Let E be the event of drawing a defective bolt. Then,
`P(E//E_1)`= probability of drawing a defective bolt, GIVEN that it is produced by the machine X `=1/100`.
`P(E//E_2)`= probability of drawing a defective bolt, given that it is produced by the machine Y
`1.5/100=15/1000=3/200`.
`P(E//E_3)`=probability of drawing a defective bolt, given that it is produced by the machine Z
`=2/100=1/50`.
Required probability
`=P(E_1//E)`
= probability that the bolt drawn is produced by X, given that it is defective
`(P(E_1).P(E//E_1))/(P(E_1).P(E//E_1)+P(E_2).P(E//E_2)+P(E_3).P(E//E_3))`
`=((1/6xx1/100))/((1/6xx1/100)+(1/3xx3/200)+(1/2xx1/50))`
`=(1/600xx600/10)=1/10=0.1`.
Hence, the required probability is 0.1.
43.

If S-= x^(2) + y^(2) + 2gx + 2fy + c= 0repre- sents a circle then show that the straight line lx + my + n = 0 (ii) meet the circle S = 0 in two points if g^(2)+f^(2)-c gt ((gl+mf-n)^(2))/((l^(2)+m^(2)))

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ANSWER :`G^(2) + f^(2) -c = ((gl+mf-n)^(2))/(L^(2)+m^(2))`
44.

For a DeltaABC the vertices are A(0, 3), B(0, 12) and C(x, 0). If the circumcircle of DeltaABC touches the x - axis, then the area (in sq. units) of the DeltaABC is

Answer»

36
27
30
24

Answer :B
45.

The maximum area of an isosceles triangle inscribed in the ellipse (x^2)/(a^2) + (y^2)/(b^2) = 1 with the vertex at one end of the major axis is

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`SQRT(3)AB`
`(3sqrt(3))/(4) ab`
`(5sqrt(3))/(4) ab`
`ab`

ANSWER :D
46.

Find |vecaxxvecb|, if veca=2hati+hatj+3hatk and vecb=3hati+5hatj-2hatk

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ANSWER :`19sqrt(2)`
47.

If P is any point common to the hyperbola (x^(2))/(16)-(y^(2))/(25)=1 and the circle having line segment joining its foci as diameter then sum of focal distances of point P is

Answer»

`6sqrt(2)`
`2sqrt(66)`
16
8

Solution :Foci of hyperbola are `(+- sqrt(41),0)`
`:. P` LIES on the circle `x^(2) + y^(2) = 41`
Any point on hyperbola is `(4 sec theta, 5 tan theta)`
`rArr 16 sec^(2) theta + 25 tan^(2) theta = 41`
`rArr tan theta = (5)/(sqrt(41))` and `sec theta = sqrt((66)/(41))`
`:. PF_(1) + PF_(2) = e (4 sec theta -(a)/(e)) +e (4 sec theta +(a)/(e))`
`= 8 esec theta = 2 sqrt(66)`
48.

Integrate the following functions. intsqrt(tanx)dx

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ANSWER :`(1)/(SQRT2)TAN^(-1)((tanx-1)/(sqrt2tanx))+(1)/(2sqrt2)log|(tanx-sqrt(2tanx)+1)/(tanx+sqrt(2tanx+1))|+c`
49.

Probability distribution of random variable X is as follows: Find its standard deviation.

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ANSWER :1.3
50.

Value of cos^(-1) (-(1)/(2)) + sin ^(-1)""(1)/(2) is:a) 2 pi b) (pi)/(2)c) pi d) none of these

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`2 PI`
`(pi)/(2)`
`pi`
NONE of these

ANSWER :C