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. |
Find the vectors from the origin to the intersection of the medians of the triangle whose vertices are A(5,2,1), B(-4,7,0) and C(5, -3,5) |
Answer» Solution : Given thatA = (5,2,1), B = (-4,7,0) C = (5,-3,5) Then position vectors of A, B, C are `5hat+2hatj`, `-4hati+7hatj`. `5hati-3hatj+5hatk` RESPECTIVELY Let G be the point of intersection of the MEDIANS of the triangleABC. Then the position of VECTOR G = `((5hati+2hatj+hatk) + (-4hati+7hatj) + (5hati-3hatj+5hatk))/3` `(6hati+6hatj+6hatk)/3` = `2hati+2hatj+2hatk` |
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| 3. |
(i) Prove that: ""^(n)P_(r) = ""^(n-1)P_(r) + r. ""^(n-1)P_(r–1) (ii) If ""^(20)C_(r+2) = ""^(20)C_(2r–3) find ""^(12)C_(r) (iii) Find the ratio ""^(20)C_(p) "to"""^(25)C_(r) when each of them has the greatest value possible. (iv) Prove that ""(n-1)C_(3) + ""^(n-1)C_(4) gt""^(n)C_(3) if n> 7 (v) Find r if ""^(15)C_(3r) = ""^(15)C_(r+3 ) |
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| 4. |
The solution of the differential equation (dy)/(dx)=(x-2y+1)/(2x-4y) is |
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Answer» `(X-2y)^(2)+2X=C` |
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| 5. |
Find the cartesian equation fo the following planes. vecr.(hati+hatj-hatk)=2 |
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| 6. |
If|z _1 |= 2and(1-i)z_2+(1+i)barz_2= 8sqrt2, then the minimumvalue of|z_1 - z_2| is ______. |
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Answer» Thisimplies that `z_(1)` lies on the circlehaving centre at origin and radius 2. `(1-i) z_(2) +(1+i) barz_(2) = 8sqrt(2)` `THEREFORE (1-i)(x_(2) + iy_(2)) +(1+i)(x_(2) -iy_(2)) = 8sqrt(2)` `rArr x_(2)+y_(2) = 4sqrt(2)` So, `z_(2)` lies on thestraightline ` + y = 4sqrt(2)` ![]() `|z_(1) -z_(2)|_("min")=` shortest distance betweencircleand straightline = AB `= OB - OA` `= 4- 2=2` |
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| 7. |
Integrate the rational functions in exercise. (cosx)/((1-sinx)(2sinx)) |
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| 8. |
The number of real solutions of the equation : cos^(7)x + sin^(4)x = 1 in the interval [-pi,pi] is : |
| Answer» Answer :A | |
| 9. |
If |{:(a+ib,c+id),(-c+id,a-ib):}|xx|{:(alpha-ibeta,gamma-idelta),(-gamma-idelta,alpha+ibeta):}|=|{:(A-iB,C-iD),(-C-iD,A+iB):}|, write down the values of A, B, C, (i=sqrt(-1)). Hence show that, the product of two sums, each of four squares, can be expressed as the sum of four squares. |
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Answer» ` C=a gamma+b delta+calpha-d beta, D=a delta-b gamma-b gamma-c beta-d alpha`, |
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| 10. |
Five dice are tossed. What is the probability that the five numbers shown will be different? |
| Answer» Answer :A | |
| 11. |
IF A be the area bounded by the x-axis and one are of the curve y= acos 3xbetween (0,0) and ((pi)/(6),0)and B be the area bounded by the x-axis and one are of the curve y=acos ^((x)/(4)) between (0,0) and (2pi,0)show that ,A : B =1: 12 |
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| 12. |
Using the properties of determinants in Exercise 1 to 6, evaluate |{:(0,xy^2,xz^2),(x^2y,0,yz^2),(x^2z,y^2z,0):}| |
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| 13. |
The value of cos^(2)45^(@)-sin^(2)15^(@) is |
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Answer» `(SQRT(3))/(2)` |
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| 14. |
The maximum value of sin x.cos x is …………. |
| Answer» Answer :B | |
| 15. |
The shortest distance of the lines bar r_1 = 4 hat i -3 hat j - hat k + lambda (2 hat i - 3 hat j + 8 hat k ) is....... |
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Answer» 3 |
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| 16. |
If from any point on the circle x^(2)+y^(2)+3gx+2fy+c=0 tangents are drawn to the circle x^(2)+y^(2)+2gx+2fy+c sin^(2)alpha+(g^(2)+f^(2)) cos^(2)alpha=0,(0 lt alpha lt(pi)/(2)) then the angle between those tangents is |
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Answer» `(pi)/(4)` |
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| 17. |
Solved the following system of linear equations by matrix inversion method.2x+5y=-2, x+2y=-3 |
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| 18. |
Prove that :int_(0)^(oo) log (x+(1)/(x)). (dx)/(1+x^(2)) = pi log_(e) 2 |
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| 19. |
Two hunters A and B set out to hunt ducks. Each of them hits as often as he misses when shooting at ducks. Hunter A shoots at 50 ducks and hunter B shoots at 51 ducks. The probabilitythat B bags more ducks than A can be expressed as (p)/(q) in its lowest form. Find the value of (p+q). |
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| 20. |
How many numbers between 6000 and 10000 can be formed using the digits 2, 3, 4, 6, 7, 9 without repetition. |
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| 21. |
If the angle between the lines having direction ratios (alpha, 3,5) and (2, -1, 2) is (pi)/(4) then alpha is: |
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Answer» 4 |
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| 22. |
If [x] denotes the greatest integer le x , then underset( n rarr oo ) ( "Lim") (1)/( n^(4)) ( [1^(3) x ]+ [2^(3) x ] +"....." +[n^(3) x ] )equals |
| Answer» ANSWER :D | |
| 23. |
Compute the magnitude of the following vectors : (i) vec(a)=2hati+3hatj+sqrt(3)hatk (ii) vec(b)=3hati-4hatk (iii) vec( c )=hati+hatj-4hatk |
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| 24. |
A biased coin with probability of getting head is twice that of tail, is tossed 4 times If a random variable X is number of heads obtained, then expected value ofX is : |
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Answer» ` ( 2 ) /(3 ) ` ` p = (2)/(3)` probability of GETTING head `q = (1)/(3)` probability of getting tail. ![]() `E(x)= Sum xi pi` ` = 0 (1)/(3^(4)) + 1XX (8)/(3^(4)) + 2 x(24)/(3^(4)) +4 xx (16)/(3^(4)) = (216)/(81)=(8)/(3)`` E (x)= (8)/(3)` . |
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| 25. |
If x=8+3sqrt(7)" and "xy=1, then the value of (1)/(x^2)+(1)/(y^2) is |
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Answer» 254 |
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| 26. |
For any two vectorsbar(a)andbar(b) , show that(1+|bara|^(2))(1+|barb|^2)=|1-bar(a).bar(b)|^(2)+|bar(a)+bar(b)+bar(a)xxbar(b)|^(2) |
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| 27. |
If veca=hati+lamdahatj+2hatk,vecb=muhati+hatj-hatk are orthogonal and |veca|=|vecb| , then (lamda,mu)= |
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Answer» `(1/4,7/4)` |
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| 28. |
Using the Rolle's theorem, determine the values of x at which the tangent is parallel to the x-axis for the following functions : (i) f(x)=x^(2)-x, x in [0,1] (ii) f(x)=(x^(2)-2x)/(x+2), x in [-1, 6] (iii) f(x)=sqrtx-(x)/(3), x in [0,9] |
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| 29. |
2[7^(-1)+3^(-1)7^(-3)+5^(-1)7^(-5)+…]= |
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Answer» `log_(e )((4)/(3))` |
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| 30. |
Transform 12x^(2)+7xy-12y^(2)-17x-31y-7=0 to rectangular through the point (1, -1) inclined at an angle tan^(-1)((4)/(3)) to the original axes. |
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| 31. |
State which of the following statements are true (T) or false(F) The line (x-1)/2=(y-1)/2=(z-1)/2 pass though the origin. |
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| 32. |
Integrate the function (sec^(2)x)/(sqrt(tan^(2)x+4)) |
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| 33. |
Differentiate (5x+8)(x^(3)+7x+9) in the way mentioned below : by expanding the product to obtain a single polynomial. |
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| 34. |
For all real values of x, the minimum value of (1+x+x^(2))/(1+x+x^(2)) is |
| Answer» ANSWER :D | |
| 35. |
Using calculus prove that log_(3) gt log_(3)5gt log_(4)7. |
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| 36. |
Evaluate (2005int_(0)^(1002)dx(sqrt(1002^(2)-x^(2))+sqrt(1003^(2)-x^(2)))+int_(1002)^(1003)sqrt(1003^(32)-x^(2))dx)/(int_(0)^(1)sqrt(1-x^(2))dx)=k, then find the sum of squares of digits of naturalnumber k. |
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| 37. |
If A_(1),A_(2)….., A_(n) are theverticesof a regularplanepolygonwith n sidesand o isits centre. Thenshowthat Sigma_(n-1)^(i-1) (overset(to)(OA)_(i) xx overset(to)(OA)_(i+1) ) =(1-n)(overset(to)(OA)_(2)xxoverset(to)(OA)_(1)) |
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Answer» <P> `:. , vec(OA)_(1) xx vec(OA)_(2) = a^(2) sin .(2pi)/(n). P` where`hat(p) ` isperpendicularto planeof polygon. Now `OVERSET(n-1)underset(i=1)(Sigma) (vec(OA)_(i) xx vec(OA)_(i+1) ) = overset(n-1)underset(i=1)(Sigma) a^(2). sin.(2pi)/(n).p` ` =(n-1) .a^(2) sin.(2pi)/(n).hat(p)` `=(n-1) [vec(OA)_(1) xx vec(OA)_(2)]` `=(1-n)[vec(OA)_(2) xx vec(OA)_(1)] =RHS` |
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| 38. |
If f(x)=unerset(x^2)overset(x^(2+1))e^(-t^2) dt then f(x) increases on |
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Answer» `(-2,2)` |
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| 39. |
Differentiate w.r.t.x the function. cot^(-1)[(sqrt(1+sin x)+sqrt(1-sin x))/(sqrt(1+sin x)-sqrt(1-sin x))],0 lt x lt (pi)/(2). |
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| 40. |
A person plays a game of tossing a coin thrice. For each head, he is given Rs 2 by the organiser of the game and for each tail, he has to give Rs 1.50 to the organiser. Let X denote the amount gained or lost by the person. Show that X is a random variable and exhibit it as a function on the sample space of the experiment. |
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| 41. |
Let I = int_1^2 (dx)/(sqrt(1 + x^2)), J = int_1^2 (dx)/(x), then |
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Answer» `I = J` |
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| 42. |
Let f(x) = {{:(int_(0)^(x){5+|1-t|}dt",","if",x gt 2),(5x + 1",","if",x le 2):} Test f(x) for continuity and differentiability for all real x. |
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| 43. |
Express the following matrices as the sum of a symmetric and a skew symmetric matrix : (i) [{:(3,5),(1,-1):}](ii)[{:(6,-2,2),(-2,3,-1),(2,-1,3):}](iii)[{:(3,3,-1),(-2,-2,1),(-4,-5,2):}](iv)[{:(1,5),(-1,2):}] |
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Answer» (II) `=[{:(6,-2,2),(-2,3,-1),(2,-1,3):}]+[{:(0,0,0),(0,0,0),(0,0,0):}]` (iii) `=[{:(3,(1)/(2),-(5)/(2)),((1)/(2),-2,-2),(-(5)/(2),-2,2):}]+[{:(0,(5)/(2),(3)/(2)),(-(5)/(2),0,3),(-(3)/(2),-3,0):}]` (iv) `=[{:(1,2),(2,2):}]+[{:(0,3),(-3,0):}]` |
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| 44. |
log_(4)2-log_(8)2+log_(16)2-....= |
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Answer» `E^(2)` |
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| 45. |
For real numbers x and y, define xRY if and only if x - y + sqrt(2) is an irrational number.Then the relation R is |
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Answer» Reflexive |
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| 46. |
Find derivatives of the following functions. 1/(x^3 + sinx)^2 |
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Answer» SOLUTION :`y = 1/{(x^3 + SINX)^2} = (x^3 + sinx)^(-2) dy/dx = -2(x^3 + sinx)^(-3)XX d/dx (x^3 + sinx) = -2/{(x^2 + sinx)^3}.(3x^2 + cosx) -{2(3x^2 + cosx)}/{(x^3 + sinx)^3}` |
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| 47. |
Sum of the squares of the first 3 terms of the given series is |
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Answer» 1100 |
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| 48. |
Let angleA=23^(@), angleB=75^(@) and angleC=82^(@) be the angles of DeltaABC. The incircle of DeltaABC touches the sides BC, CA, AB at points D, E, F respectively. Let r', r_(1)^(') respectively be the inradius, exradius opposite to vertex D of DeltaDEF and r be inradiusof DeltaABC, then Q.(r_(1)^('))/(r )= |
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Answer» `"sin"(A)/(2)+"sin"(B)/(2)+"sin"(C )/(2)-1` |
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| 49. |
If A is a matrix of order 3, such that A(adj A) = 10 I, then find |adj A| = |
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Answer» 1 |
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| 50. |
Let angleA=23^(@), angleB=75^(@) and angleC=82^(@) be the angles of DeltaABC. The incircle of DeltaABC touches the sides BC, CA, AB at points D, E, F respectively. Let r', r_(1)^(') respectively be the inradius, exradius opposite to vertex D of DeltaDEF and r be inradiusof DeltaABC, then Q.(r')/(r)= |
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Answer» `"sin"(A)/(2)+"sin"(B)/(2)+"sin"(C )/(2)-1` |
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