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. |
Solve 24x lt100 , when x is a natural number. |
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| 3. |
SetA,B,C, A cap B, A cap B, Acap C, B cap C and A cap B cap Chave 35, 40, 45, 13, 12, 14 and 5 elements respectively. An element is selected at random from the set a cup V cup C . The probability thatthe selected elementbelongs to only set A is |
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Answer» `(13)/(86)` |
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| 4. |
Let f : [1/2, 1] to R (the set of all real numbers) be a positive, non -constant and differentiable function such that the f'(x) < 2 f(x) and f(1/2) = 1. Then the value of int_(1//2)^(1) f(x) dx lies in the interval : |
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Answer» `(2e - 1, 2e)` |
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| 5. |
1.5 ml of the gaseous hydrocarbonrequired 375 ml of air (containing 20% O_(2) by volume) for complete combustion. The resultantgaseous mixture occupied 345 ml. The formula of the hyrocarbonis |
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Answer» `C_(4)H_(8)` |
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| 6. |
If the normal at (1,2) on the parabola y^(2)=4x meets the parabola again at the point (t^(2),2t) then the value of t is |
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Answer» 1 |
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| 7. |
Evaluate (ii) int_(a)^(b) sqrt((x-a)/(b-x))dx (a lt x lt b) |
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| 8. |
A function f: R rarr R satisfies the equation f(x+ y)= f(x).f(y) "for all" x, y in R, f(x) ne 0. Suppose that the function is differentiable at x=0 and f'(0)=2, then prove that f'(x)= 2f(x) |
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| 9. |
Two gases N_(2)and H_(2) are allowed to react from mixture of N_(2)H_(2)(1) and N_(2)H_(4)(g) leaving none of the reactants. Formation of N_(2)H_(2) (1) does not create any energy change whereas formation of 1 ml N_(2)H_(4)(g) absorbs 2 Joule energy. Ratio of volume contraction to energy change (in ml/Joule) during reaction when 30 ml N_(2)and 40 ml H_(2) react under similar conditions of temperature and pressure. |
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Answer» Solution :`N_(2)+H_(2)toN_(2)H_(2)(1)+N_(2)H_(4)(g)` `POAC on H ""a ML""bml` `30xx2=2a+2bimpliesa+b=30` `POAC on H40xx2=2a+4bimpliesa+2b=30` `b=10,a=20` `V.C.=(30+40)-10=60ml` Energy change `=10xx2=20` `(V.C.)/("Energy change")=(60)/(20)=3` |
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| 10. |
Solve the following systems of linear inequalities graphically : x lt y, x gt 0 , y lt 1. |
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Answer» Solution :`x LT y` `x gt 0` `y lt 1` Step - Let US CONSIDER the POINT (1,0) that does not lie on these lines. Putting x = 0 , y = 0 in the inequations we get clearly (1,0) satisfies x`gt`0, y `lt` 1 but does not satisfy x `lt` y. `therefore` The shaded region is the solution region. |
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| 11. |
The solution vectors vecr of the equation vecr xx hati=hatj+hatk and vecr xx hatj=hatk+hatj represent two straight lines which are : |
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Answer» INTERSECTING |
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| 12. |
If P(A)= (2)/(5), P(B)= (3)/(10) and P(A cap B)= (1)/(5) , then P(A'//B') * P(B'//A') is equal to ………. |
| Answer» Answer :C | |
| 13. |
If (0,-3) is one limiting point of a coaxal system of circlesx^(2) + y^(2) + 4y + 7 = 0is a member , then the other limiting point is |
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Answer» (-2,-2) |
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| 14. |
Find (dy)/(dx) of the functions given in Exercises 12 to 15. xy= e^((x-y)). |
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| 15. |
Let vec(a)=hati+hatj+hatk,vec(b)=hati and vec( c )=c_(1)hati+c_(2)hatj+c_(3)hatk. Then If c_(1)=1 and c_(2)=2 find c_(3) which makes vec(a),vec(b) and vec( c ) coplanar. |
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| 16. |
int_(0)^(pi)(x dx)/(1+sin x) |
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Answer» Solution :`"Let I"= int_(0)^(pi) (x)/(1+sinx)DX` `RARR ""I=int_(0)^(pi) (pi-x)/(1+sin (pi-x))dx` `=int_(0)^(pi)(pi-x)/(1+sin x)dx` Adding equations (1) and (2) `2I =int_(0)^(pi)(x+pi-x)/(1+sin x)dx` `=piint_(0)^(pi)(1)/(1+sinx).(1-sin x)/(1-sin x)dx` `=piint_(0)^(pi)(1-sinx)/(1-sin^(2)x)dx` `=pi int_(0)^(pi)(1-sinx)/(COS^(2)x)dx` `=pi int_(0)^(pi)(sec^(2)x-secx tan x) dx` `=pi [tan x-sec x]_(0)^(pi)` `=pi [(tan pi-sec pi)-(tan 0-sec 0)]` ` =pi (1+1) =2pi` `rArr ""I=pi` |
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| 17. |
int(logx+(1)/(x^(2)))e^(x)dx=..........+c |
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Answer» `e^(x)(logx+(1)/(x^(2)))` |
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| 19. |
The slopes of the lines given by 12x^(2)+bxy-y^(2)=0 differ by 6, Then value of b is |
| Answer» ANSWER :C | |
| 20. |
We know that , ifa_(1),a_(2),….a_(n) are in A.P and vice versa . If a_(1),a_(2),…a_(n)are in A.P and viceversa . If a_(1),a_(2)….a_(n) are in A.Pwith common difference d, then for nay b ( gt 0) the numbersb^(a_(1)),b^(a_(2)),b^(a_(3)),....,b^(a_(n)) are in G.Pwith commonratio b^(d) If a_(1),a_(2),.....a_(n) are positive and in G.P with common ratio r , then for any base b(b gt 0), log_(b) a_(1) , log _(b) a_(2) , ..., log_(b) a_(n) are in A.P with common differencelog_(b)r If p,q,r are in A.P , then the pth , the qth , therth terms of any G.P are in |
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Answer» A.P |
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| 21. |
Two events E and F are independent. If P(E ) = 0.3and P(E cup F)= 0.5 ,then P(E//F)- P(F//E) equal ……… |
| Answer» Answer :C | |
| 22. |
Consider a triangle ABC with sides AB and AC having the equations L_1 = 0 and L_2 = 0 . Let the centroid, orthocentre and circumcentre of the Delta ABCare G, H and S respectively. L = 0 denotes the equation of side BC. If L_1 : x+y – 1=0 and L_2 : 2x – y + 4=0and S(2, 1) then find the x-intercept of the line L = 0. |
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| 23. |
We know that , ifa_(1),a_(2),….a_(n) are in A.P and vice versa . If a_(1),a_(2),…a_(n)are in A.P and viceversa . If a_(1),a_(2)….a_(n) are in A.Pwith common difference d, then for nay(b gt 0) the numbersb^(a_(1)),b^(a_(2)),b^(a_(3)),....,b^(a_(n)) are in G.Pwith commonratio b^(d) If a_(1),a_(2),.....a_(n) are positive and in G.P with common ratio r , then for any base b(b gt 0), log_(b) a_(1) , log _(b) a_(2) , ..., log_(b) a_(n) are in A.P with common differencelog_(b)r If a,b,c,d are in G.P and a^(x) = b^(y) = c^(z) = d^(v) , then x, y , z , v are in |
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Answer» A.P |
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| 24. |
int_(0)^(1) (x-1) e^(-x) dx= |
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Answer» `- 1/e` |
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| 25. |
We know that , ifa_(1),a_(2),….a_(n) are in A.P and vice versa . If a_(1),a_(2),…a_(n)are in A.P and viceversa . If a_(1),a_(2)….a_(n) are in A.Pwith common difference d, then for nay b ( gt 0) the numbersb^(a_(1)),b^(a_(2)),b^(a_(3)),....,b^(a_(n)) are in G.Pwith commonratio b^(d) If a_(1),a_(2),.....a_(n) are positive and in G.P with common ratio r , then for any base b(b gt 0), log_(b) a_(1) , log _(b) a_(2) , ..., log_(b) a_(n) are in A.P with common differencelog_(b)r Ifx, y , zare respectively the pth , qth and the rthtermsof an A.P ..., A.P.., as well as of a G.P , then x^(y-z),y^(z-x).z^(x-y) is equal to |
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Answer» p |
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| 26. |
Find the condition that x^3-px^2+qx-r=0 may have the roots in G.P . |
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| 27. |
Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the probability that (i) both balls are red. (ii) first ball is black and second is red. (iii) one of them is black and other is red. |
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| 28. |
If f: R to R, g: R to R and h: R to R is such that f(x)=x^(2), g(x)= tan x and h (x)= logx then the value of [ho (gof)]x , if x=(sqrt(pi))/(2) will be |
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Answer» 0 |
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| 29. |
Consider a triangle ABC with sides AB and AC having the equations L_1 = 0 and L_2 = 0 . Let the centroid, orthocentre and circumcentre of the Delta ABCare G, H and S respectively. L = 0 denotes the equation of side BC. If L_1 : 2x + y = 0 and L_2 : x – y + 2 = 0and H(2, 3) then find the y-intercept of L = 0. |
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| 30. |
If the position vectors of the points A,B,C are -2bar(i)+bar(j)-bar(k), -4bar(i)+2bar(j)+2bar(k), 6bar(i)-3bar(j)-13bar(k) respectively and bar(AB) = lambda bar(AC) then find the value of lambda. |
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| 31. |
Evaluation of definite integrals by subsitiution and properties of its : f(x)=|(sinx+sin2x+sin3x,sin2x,sin3x),(3+4sinx,3,4sinx),(1+sinx,sinx,1)| then int_(0)^(pi/2)f(x)dx=………. |
| Answer» Answer :C | |
| 32. |
Show that the vectors bar(a) = 2 hat(i) - 3 hat(j) + 4 hat(k) and bar(b) = -4 hat(i) + 6 hat(j) - 8k are collinear. |
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| 33. |
The straight line x + y + 1 = 0 bisects an angle between a pair of lines, of which one is 2x - 3y + 4 = 0 . Then the equation of the other line in that pair is |
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Answer» 2x + 3Y + 4 = 0 |
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| 34. |
Consider the integral int_(-2)^(2) (dx)/(4 + x^(2)) . Itis easy to conclude that it is equal to (pi)/(4) .Indeed int_(-2)^(2) (dx)/(4 + x^(2)) = (1)/(2) "arc tan "(x)/(2) |_(-2)^(2)= (1)/(2) [(pi)/(4) - (-(pi)/(4))]= (pi)/(4)On the other hand, making the substitution x = (1)/(t) we havedx = - (dt)/(t^(2))|{:(x," "t),(-2,-1//2),(2,1//2):}| int_(-2)^(2) (dx)/( 4 + x^(2)) = - int_(-1//2)^(1//2) (dt)/(t^(2)(4 + (1)/(t^(2))))= - int _(-1//2)^(+1//2) (dt)/(4t^(2) + 1)=(1)/(2) "arc tan 2t |_((1)/(2))^((1)/(2)) = - (pi)/(4) This result is obviously wrong, since the integrand (1)/(4 + x^(2)) gt0 , andconsequently, thedefinite integral of this function cannot be equal to a negative number -(pi)/(4) . Find the mistake . |
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| 35. |
Let g be the inverse function of f and f '(x) = (x^(10))/(1+x^(2)) if g(2) = a then g'(2) is equal to: |
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Answer» `(a)/(2^(10))` `RARR f'(g(x)).g'(x)=1` `rArr g'(x)=(1)/(f'(g(x)))=(1+(g(x))^(2))/((g(x))^(10))` `rArr g'(2)=(1+(g(2))^(2))/((g(2))^(10))` |
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| 36. |
Area of the triangle is calculated by the formula A=(1)/(2)ab sin C. If C = (pi)/(6) and error in the measure of C is x%, find the approximate change in the area of the triangle. Where a and b are constant. |
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| 37. |
If the equation x^(2)-cx+d=0 has roots equal to the fourth powers of the roots of x^(2)+ax+b=0, where a^(2)gt4b, then the roots of x^(2)-4bx+2b^(2)-c=0 will be |
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Answer» both REAL |
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| 38. |
Integrate the following rational functions : int(dx)/(x(x+2)) |
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| 39. |
Find the mean deviation about mean of first 2n+1 natural numbers from mean. |
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| 40. |
Find the equation of the circle with centre (-3, 4)and touching y-axis. |
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| 42. |
Prove that if (a + b+ c)(b + c - a) = 3bc then A = 60^@ |
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Answer» SOLUTION :(a + B + c)(b + c + a) =3bc or, ab + ca - a^2 + b^2 + BC - ab + bc + c^2 - ca = 3bc` or, `b^2 + c^2 -a^2 = bc` or, `(b^2 + c^2 - a^2)/(2bc) = 1/2` or, COSA = 1/2 or , A = `60^@` |
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| 43. |
If the lines L_1 and L_2in space are defined by L_1 = {x=sqrt lambda y+ (lambda-1) z= (sqrtlamda -1) y+sqrtlambda ) and L_2 ={ x=sqrtmu y + (1-sqrtmu ), z =(1-sqrtmu )y +sqrtmu )thenL_ 1is perpendicular to L_2 for all non- negative realslambda and musuch that |
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Answer» ` sqrtlambda +SQRT mu =1` |
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| 44. |
For any positive integers m, n (with n ge m) If ({:(n),(m):}) = .^(n)C_(m) Prove that ({:(n),(m):}) + ({:(n - 1),(m):}) + ({:(n - 2),(m):}) + … + ({:(m),(m):}) = ({:(n + 1),(m + 1):}) Prove that ({:(n),(m):}) + 2 ({:(n + 1),(m):}) + 3 ({:(n - 2),(m):}) + .... + (n - m + 1) ({:(m),(m):}) = ({:(n + 2),(m + 2):}) |
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Answer» Solution : Let `S = ((n)/(m))+((n-1)/(m)) + ((n-2)/(m))+ ((n-2)/(m)) +.....+((m)/(m)) =((n+1)/(m+1)).....(i)` It is obvious that, `n ge m` Note : Thisquestion is based UPON additive loop. Now ,`S =((m)/(m)) + ((m+1)/(m)) + ((m+2)/(m)) +.......+((n)/(m))` ` ={((m+1)/(m+1))+((m+1)/(m))}[because ((m)/(m)) = 1= ((m+1)/(m+1))]` `= ((m+2)/(m+1)) + ((m+2))/(m)) + ......+ ((n)/(m))""[because""^(n)C_(R)+ ""^(n)C_(r+1) = ""^(n+1)C_(r+1)]` `=((m+2)/(m+1)) +......+((n)/(m))` `=.............` ` =((n)/(m+1))+((n)/(m)) = ((n+1)/(m+1))` whichis ture....(ii) Again, we haveto prove that `((n)/(m))+2((n-1)/(m)) + 3((n-2)/(m)) +......+ (n-m+1)((m)/(m)) = ((m+2)/(m+2))` Let`S_(1) = ((n)/(m))+2((n-1)/(m)) +3((n-2)/(m)) +......+(n-m+1)((mm)/(m))` `{:(= ((n)/(m)) + ((n-1)/(m)) + ((n-2)/(m)) +...+ ((m)/(m))), ( ""+ ((n-1)/(m)) + ((n-2)/(m)) +...+ ((m)/(m))), (""+ ((n-2)/(m)) +...+((m)/(m)) ),(""...) , (""+ ((m)/(m))):}}n-m + 1` rows Now, SUM of the first row is `((n+1)/(m+1))` Sum of the second row is `((n)/(m+1))` Sumof thethird row is `((n+1)/(m+1))`, .................... Sum of the last row is `((m)/(m)) = ((m+1)/(m+1))` THUS `S = ((n+1)/(m+1))+((n)/(m+1)) + ((n +1)/(m+1))+.......+ ((m+1)/(m+1)) = ((n+1+1)/(m+2)) = ((n+2)/(m+2))` [from Eq. (i) replacing nbyn +1 and m by m + 1] |
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| 45. |
Leta ne 0and p(x )be apolynomialof degreegreaterthan2.If P(x )leavesremaindera and-awhendividedrespectivelybyx+aand x-athentheremainderwhenp(X )isdividedbyx^2 -a^2 is |
| Answer» ANSWER :D | |
| 46. |
Evaluate int x^(2) tan^(-1) x dx |
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| 47. |
Find Order and Degree of given differential equation ((ds)/(dt))^(4) + 3s(d^(2)s)/(dt^(2)) = 0 |
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| 48. |
What are the coordinates of the point P in the xy-plane that divides the line segment whose endpoints are A(-2, 9) and B(7, 3) into two segments such that the ratio of AP to PB is 1 to 2? |
| Answer» Answer :C | |
| 49. |
If lim_(x rarr 0) (1+px)^(q//x) = e^(4), where p, q, in N, then : |
| Answer» Answer :D | |