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.

The derivative of `sin^2x`with respect to `cos^2x`is equal to....A. `tan^2x`B. `tanx`C. `-tanx`D. None of these

Answer» Correct Answer - D
Let `u=sin^2xxand v=cos^2x`
On differenting w.r.t.x, respectively , we get
`(du)/(dx)=2sinx cos x`
and `(dv)/(dx)=-2sinxcosx`
`therefore (du)/(dv)=(du//dx)/(dv//dx)=(2sinxcosx)/(-2sinxcosx)=-1`
2.

STATEMENT - 1 : If `x^(2)+2x+3=0` and `7x^(2)+lx+k = 0` have a common roots, then `l+k = 35`. Given `l, k epsilon R`. STATEMENT - 2 : If `a, b, c epsilon R` and roots of a quadratic equation `ax^(2)+bx+c=0` are imaginary then roots occurs in conjugate pair.A. STATEMENT - 1 is True, STATEMENT- 2 is True , STATEMENT - 2 is a correct explanation for STATEMENT - 1B. STATEMENT - 1 is True, STATEMENT - 2 is True , STATEMENT - 2 is NOT a correct explanation for STATEMENT - 1C. STATEMENT -1 is True, STATEMENT - 2 is FalseD. STATEMENT -1 is False, STATEMENT - 2 is True

Answer» Correct Answer - A
Statement -1 : If `x^(2)+2x +` ………..
`x^(2)+2x+3=0` has imaginary roots and `l, k epsilon R`
`:. 7x^(2)+lx+k = 0` has an imaginary root
Since imaginary roots are in conjugate pair
`:.` Both the roots are common
Thus `(7)/(1) = (l)/(2) = (k)/(3) implies l = 14, k = 21`
`:. l + k = 35`.
3.

A vertex of common graph of inequalities `2x+y ge 2` and `x-y le 3` , isA. `(0,0)`B. `((5)/(3),-(4)/(3))`C. `((5)/(3),(4)/(3))`D. `(-(4)/(3),(5)/(3))`

Answer» Correct Answer - B
To find a common vertex of inequalities `2x+y ge 2 and x-yle 3`, solve the following equations
`2x+y=2`.......(i)
and `x-y=3`...(ii)
On solving Eqs. (i) and (ii) , we get
`x=(5)/(3) and y=-(4)/(3)` .
4.

If `x` and `y` satisfy the equation `y = 2[x]+9` and `y = 3[x+2]` simultaneously, the `[x+y]` is (where `[x]` is the greatest integer function)A. `21`B. `18`C. `30`D. `12`

Answer» Correct Answer - B
If `x` and `y` satisfy ………..
`y = 2[x]+9, y=3[x+2]=3[x]+6`
`:. [x]=3, y = 15`
`:. [x+y]=[x]+y=18`
5.

`(d)/(dx)[sin^(-1)(xsqrt(1 - x)- sqrt(x)sqrt(1 - x^(2)))]` is equal toA. `(1)/(2sqrt(x(1-x)))-(1)/(sqrt(1-x^2))`B. `(1)/(sqrt(1-{xsqrt(1-x)-sqrt(x(1-x^2))}^2))`C. `(1)/(sqrt(1-x^2))-(1)/(2sqrt(x(1-x)))`D. `(1)/(sqrt(x(1-x)(1-x)^2))`

Answer» Correct Answer - C
Let `y=sin^(-1)[xsqrt(1-x)-sqrt(1-x^2)]`
Put `x=sin alpha and sqrt(x)= sin beta`
`therefore y=sin^(-1)[sinalphasqrt(1-sin^(2)beta)-sinbetasqrt(1-sin^(2)alpha)]=sin^(-1)[sin(alpha-beta)]=alpha-beta`
`=sin^(-1)x-sin^(-1)sqrt(x)`
`rArr (dy)/(dx)=(1)/(sqrt(1-x^2))-(1)/(sqrt(1-x)).(1)/(2sqrt(x))=(1)/(sqrt(1-x^2))-(1)/(2sqrt(x(1-x)))`
6.

Let truth values of p be F and q be T. then , truth vlaue of `~(~p v q)` isA. TB. FC. Either T or FD. Neither T or F

Answer» Correct Answer - B
Since , truth values of p and q are Fand T, respectively. Therefore , truth value of `~(~p vv q)` is F.
7.

If `a = underset(55 "times")underbrace(111.....1), b= 1+10+10^(2)+10^(3)+10^(4) and c=1+10^(5)+10^(10)+……+10^(50)` thenA. `b, (a)/(2), c` are in `A.P`B. `b, sqrt(a), c` are in `G.P`C. `a` is `a` prime numberD. `a` is `a` composite number

Answer» Correct Answer - B::D
If `a = underset(55 "times")underbrace(111....1)` ………….
`a = underset(55 "times")underbrace(111....1) = 1+10+10^(2)+……+10^(54)= (10^(55)-1)/(9)`
`b=1+10+10^(2)+10^(2)+10^(3)+10^(4)= (10^(5)-1)/(9)`
`c=1+10^(5)+10^(10)+……+10^(50)`
`= ((10^(5))^(11)-1)/(10^(5)-1)=(10^(55)-1)/(10^(5)-1)=(((10^(55)-1)/9)/(10^(5)-1))/(9) =(a)/(b)`
`a = bc :. b, sqrt(a) , c are in G.P`
8.

What must be the matrix X , is `2X+[[1,2],[3,4]]=[[3,8],[7,2]]?`A. `[[1,3],[2,-1]]`B. `[[1,-3],[2,-1]]`C. `[[2,6],[4,-2]]`D. `[[2,-6],[4,-2]]`

Answer» Correct Answer - A
`2X+[[1,2],[3,4]]=[[3,8],[7,2]]`
`rArr 2X=[[3,8],[7,2]]=[[1,2],[3,4]]`
`=[[2,6],[4,-2]]`
`X=[[1,3],[2,-1]]`
9.

The lines `2x + y -1=0`, `ax+ 3y-3=0` and `3x + 2y -2=0` are concurrent for -A. All aB. a= 4 onlyC. `1 le a le 3`D. `a lt 0` only

Answer» Correct Answer - 1
`|{:(2,1,-1),(a,3,-3),(3,2,-2):}|`
10.

If a,b,c are in A.P., then `10^(ax+10),10^(bx+10)`,10^(ex +10)` are in -A. A.PB. G.P only when `x gt0`C. G.P for all xD. G.P only when `x lt0`

Answer» Correct Answer - 3
We have : `2bx = ax + cx`
`2(bx + 10) =(ax + 10) + (cx + 10)`
`10^(2(bx + 10)) = 10 ^((ax + 10)+(cx+10))`
`(10^(bx + 10))^(2) = (10^(ax+10)).(10^(cx +10))`
i.e., Number are in G.P
11.

If `A, B, C` are angles of `Delta ABC` and `tan A tan C = 3, tan B tan C = 6`, thenA. `A = (pi)/(4)`B. `tan A tan B = 2`C. `(tan A)/(tan C) = (3)/(2)`D. `tan^(3)A+tan^(3)B=tan^(3)C+3tan A tan B tan C`

Answer» Correct Answer - A::B
If `A, B, C` are …………..
`tan A + tan B + tan C = tan A tan B tan C = 3 tan B = 6 tan A`
`:. 3 tan A + tan C = tan A`
`tan C = 3 tan A`
`:. Tna A+ 2tan A + 3 tna A = tan A. 2tan A . 3 tan a i.e.`
`tan A = tan^(3)A`
`i.e. tan^(2)A=1 i.e. tan A = 1`
`:. A = (pi)/(4)`
`:. tan A tna B = 2 tan^(2)A = 2`
12.

The angle between two planes `x+2y+2z=3` and `-5x+3y+4z=9` isA. `cos^(-1).(0sqrt(2))/(20)`B. `cos^(-1).(3sqrt(2))/(5)`C. `cos^(-1).(3sqrt(2))/(10)`D. `cos^(-1).(19sqrt(2))/(30)`

Answer» Correct Answer - C
Here , `a_1=1,b_1=2,c_1=2`
and `a_2=-5,b_2=3, c_2=4`
`therefore cos theta =(1xx (-5)+2xx3+2xx4)/(sqrt(1+2^2+2^2)sqrt(5^2)+3^2+4^2)=(-5+6+8)/(sqrt(9)+sqrt(50))=(3sqrt(2))/(10)`
`rArr theta=cos^(-1)((3sqrt(2))/(10))`
13.

Find the value of `k`, so that the equation `2x^2+kx-5=0` and `x^2-3x-4=0` may have one root in common.A. `-3`B. `-1`C. `-(27)/(4)`D. `(27)/(4)`

Answer» Correct Answer - A::C
The value of `K` ………….
`x^(2)-3x-4=0`
`(x-4) (x+1) = 0`
`x = -1, 4`
when `x = -1`
`2.1 - k - 5 = 0`
`k = -3`
when `x =4`
`32+4k- 5 =0`
`k = -27//4`
14.

The number of integral solutions of the inequation `x+y+z le 100, (x ge 2, y ge 3, z ge 4)` , isA. `.^(100)C_(2)`B. `.^(94)C_(3)`C. `.^(93)C_(2)`D. None of these

Answer» Correct Answer - A
15.

Number of ways in which four different toys and five indistinguishable marbles can be distributed between 3 boys, if each boy receives at least one toy and at least one marbleA. 42B. 100C. 150D. 216

Answer» Correct Answer - A
16.

Let N be the number of quadratic equations with coefficients from {0,1, 2, 3,..., 9} such that 0 is a solution of eachequation. Then the value of N is`2^9`(b) infinite (c)90 (d) 900A. `2^(9)`B. infiniteC. 90D. 900

Answer» Correct Answer - A
17.

If `f(x)=cos[pi^(2)]x+cos[-pi^(2)]x`, where `[x]` stands for the greatest integer function, thenA. `f ((pi)/(2))= -1`B. `f(pi)=1`C. `f(-pi)=0`D. `f((pi)/(4))= (-1)/(sqrt(2))`

Answer» Correct Answer - A::C::D
Let `f(x) = cos` …………..
`2pi^(2)=19.72`
`3pi^(2)=29.58`
`:. [2pi^(2)]=19, [-3pi^(2)]= -30`
`f ((pi)/(2))= -1 , f(pi) = 0 , f(-pi) = 0 , f ((pi)/(4)) = (-1)/(sqrt(2))`
18.

`intsqrt(1+sin((x)/(4)))dx` is equal toA. `B(sin.(x)/(8)-cos.(x)/(8))+c`B. `(sin.(x)/(8)+cos.(x)/(8))+c`C. `(1)/(8)(sin.(x)/(8)-cos.(x)/(8))+c`D. `8(cos.(x)/(8)-sin.(x)/(8))+c`

Answer» Correct Answer - A
We know that ,
`sqrt(1+sin2theta)=sintheta+costheta`
`intsqrt(1+sin.(x)/(4))dx`
`=int(sin.(x)/(8) +cos.(x)/(8))dx`
`=-8cos.(x)/(8)+8sin.(x)/(8)+c`
`=8(sin.(x)/(8)-cos.(x)/(8))+c`
19.

In how any ways can 8 different books be distributed among 3 studentsif each receives at least 2 books?A. 2940B. 2600C. 2409D. 2446

Answer» Correct Answer - A
20.

The coordinates of a point on the line `(x-1)/(2)=(y+1)/(-3)=z` at a distance `4sqrt(14)` form the point (1, -1,0), isA. `(-13,9,4)`B. `(-7, 11,-4)`C. `(11,-7,-4)`D. None of these

Answer» Correct Answer - 2
Any point on the given line is
`rArr Q (2lambda + 1,-3lambda-1,lambda)`
& P(1,-1,0)
Given `PQ =4sqrt(4)`
`rArr (2lambda)^(2) + (-3lambda)^(2)+lambda^(2) = (4sqrt(14))^(2)`
`rArr 14lambda^(2) = 16 xx14`
`rArrlambda = pm 4`
`therefore` Coordinates are `rArr (9,-13,4) & (-7, 11,-4)`
21.

If `(7+4sqrt(3))^(x^(2-8))+(7-4sqrt(3))^(x^(2-8))=14, then x=`

Answer» Correct Answer - 6
Sum of solutions ………..
Take `(7+4sqrt(3))^(x^(2)-4x+3)=t`
`(7+4sqrt(3))^(x^(2)-4x+3)=t` thus, equastion becomes
`t+(1)/(t)=14, t^(2)-14t+1=0`
`t = (14+-8sqrt(3))/(2) = 7 +-4sqrt(3)`
thus `x^(2)-4x+3=1, -1 implies x = 2,2 +- sqrt(2)`
22.

A dictionary is made of the words that can be the position of the word "PARKAR" What is position of the word PARKAR in that dictionary if words are printed in the same order as that of ordinary dictionary?A. 98B. 99C. 100D. 101

Answer» Correct Answer - A
23.

If roots of the equation `x^2-2ax+a^2+a-3=0` are real and less than 3 then `a) a lt 2` b)`2 le a le 3` c) `3 l3 a le 4` d)` a gt 4`A. `a lt 2`B. `2 le a le 3`C. `3 lt a le 4`D. `a gt 4`

Answer» Correct Answer - A
24.

If `a^(2)+b^(2)+c^(2)-2a-4b6c= -14` then `a+b+c =`

Answer» Correct Answer - 3
If `a^(2)+b^(2)+c^(2)`…………
`a^(2)+b^(2)+c^(2)-2a-4b-6c+14=0`
`implies (a-1)^(2)+(b-2)^(2)+(c-3)^(2)=0`
`implies a-1=0, b-2=0, c-3 = 0`
`implies a+b+c=6`
25.

STATEMENT - 1 : The term independent of x in the expansion of `(x+1/x+2)^(m)` is `((2m) !)/((m !)^(2))` STATEMENT - 2 : The coefficient of `x^(b)` in the expansion of `(1+x)^(n)` is `.^(n)C_(b)`.A. STATEMENT - 1 is true, STATEMENT - 2 is true and STATEMENT - 2 is correct explanation for STATEMENT - 1.B. STATEMENT - 1 is true, STATEMENT - 2 is true and STATEMENT - 2 is not correct explanation for STATEMENT - 1.C. STATEMENT-1 is true, STATEMENT-2 is falseD. STATEMENT-1 is false, STATEMENT-2 is true

Answer» Correct Answer - A
26.

If `x^(2)+y^(2)=4`, then maximum value of `((x^(3)+y^(3))/(x+y))` is

Answer» Correct Answer - 6
If `x^(2)+y^(2)=4`, …………
`x^(2)+y^(2)=4`
`x = 2 cos theta, y = 2sin theta`
`(x^(3)+y^(3))/(x+y) = x^(2)+y^(2)-xy= 4 -2 sin 2theta`
masx.value `= 4-(2)(-1)=6`
27.

Number of solutions of equation `sin x.sqrt(8cos^(2)x)=1` in `[0, 2pi]` are

Answer» Correct Answer - 4
Number of solutions……….
Solutions are possible when `sin x gt 0 i.e.,x epsilon(0, pi)`
case I `x epsilon(0, (pi)/(2)], sin2x=(1)/(sqrt(2))`
`implies 2x = (pi)/(4), (3pi)/(4) implies x = (pi)/(8), (3pi)/(8)`
case II `x in[(pi)/(2), pi], sin2x = (-1)/(sqrt(2))`
`implies 2x = (5pi)/(4), (7pi)/(4) implies x = (5pi)/(8), (7pi)/(8)`
28.

The coefficients of three consecutive terms of `(1+x)^(n+5)`are in the ratio 5:10:14. Then `n=`___________.A. 4B. 5C. 6D. 7

Answer» Correct Answer - A
29.

The co-efficient of x in the expansion of `(1-2x^3+3x^5)(1+1/x)^8` is:A. 56B. 65C. 154D. 62

Answer» Correct Answer - A
30.

In the following question, a number series is given, after the number series, a number and then A, B, C, D and E are given. Compete the number series starting from the given number based on the pattern of the original number series and choose correct option.18202432488019ABCDE What will come in place of ‘E’?1. 802. 713. 914. 815. 65

Answer» Correct Answer - Option 4 : 81

The pattern of the original number series is

⇒ 18 + 21 = 20

⇒ 20 + 22 = 24

⇒ 24 + 23 = 32

⇒ 32 + 24 = 48

⇒ 48 + 25 = 80

According the pattern of the above series the number series starting from the given number would be as:

⇒ A = 19 + 21 = 21

⇒ B = 21 + 22 = 25

⇒ C = 25 + 23 = 33

⇒ D = 33 + 24 = 49

⇒ E = 49 + 25 = 81

The required number in place of E would be 81.

31.

In the following question, a number series is given, after the number series, a number and then A, B, C, D and E are given. Compete the number series starting from the given number based on the pattern of the original number series and choose correct option.303164195784392519ABCDE What will come in place of ‘E’?1. 25052. 26153. 26054. 39255. 2600

Answer» Correct Answer - Option 3 : 2605

The pattern of the original number series is

⇒ 30 × 1 + 1 = 31

⇒ 31 × 2 + 2 = 64

⇒ 64 × 3 + 3 = 195

⇒ 195 × 4 + 4 = 784

⇒ 784 × 5 + 5 = 3925

According the pattern of the above series the number series starting from the given number would be as:

⇒ A = 19 × 1 + 1 = 20

⇒ B = 20 × 2 + 2 = 42

⇒ C = 42 × 3 + 3 = 129

⇒ D = 129 × 4 + 4 = 520

⇒ E = 520 × 5 + 5 = 2605

The required number in place of E would be 2605.

32.

Which of the following is an objective function?(A) x > 5 (B) z = 11x + 19y (C) z ≥ 0 (D) None of these

Answer»

Option : (B) z = 11x + 19y

33.

If `a in [-20,0]`, then the probability that the graph of the function `y=16x^(2)+8(a+5)x-7a-5` touches or above the x-aixs isA. `(3)/(20)`B. `(13)/(20)`C. `(7)/(20)`D. `(1)/(2)`

Answer» Correct Answer - B
`a in [-20,0]`
`because` Graph of the function `y=16x^(2)+8(a+5)x-7a-5` touches or above the x-axis
`implies Dle0implies 64(a+5)^(2)+64(7a+5)le0impliesa^(2)+17a+30le0impliesa in [-10,-3]" "therefore "Probability" P(7)/(20)`
34.

Find the angle between the surfaces z = x2+y2-3 and x2+y2+z2=9 at (2,-1,2).

Answer»

Given surfaces are

z = x2 + y2 – 3

\(\Rightarrow\) x2 + y2 – z = 3

And x2 + y2 + z2 = 9

let \(\phi_1\) = x2 + y2 – z

And \(\phi_2\) = x2 + y2 + z2

Given point (2, –1, 2).

\(\vec \nabla \phi_1 = \vec \nabla(\mathrm x^2+y^2-z)\)

\(=\hat i\frac{\partial}{\partial \mathrm x}(\mathrm x^2+y^2-z)\) \(+\hat j\frac{\partial}{\partial \mathrm x}(\mathrm x^2+y^2-z)\) \(+\hat k \frac{\partial }{\partial z}(\mathrm x^2+y^2-z)\)

\(=2\mathrm x \hat i + 2y\hat j-\hat k\)

\((\vec \nabla\phi_1)_{(2, -1, 2) }= 4 \hat i -2\hat j-\hat k\)

\(\vec \nabla \phi_2=\vec \nabla(\mathrm x^2+y^2+z^2)\)

\(=\hat i\frac{\partial}{\partial \mathrm x}(\mathrm x^2+y^2+z^2)\) \(+\hat j \frac{\partial}{\partial y}(\mathrm x^2+y^2+z^2)\) \(+\hat k\frac{\partial}{\partial z}(\mathrm x^2+y^2+z^2)\)

\(=2\mathrm x \hat i+2y\hat j + 2z\hat k\)

\((\vec \nabla \phi_2)_{(2, -1, 2)}=4\hat i-2\hat j+4\hat k\)

let angle between surfaces \(\phi_1\) and \(\phi_2\) is θ.

Then \(\vec \nabla\phi_1.\vec \nabla \phi_2\) \(=|\vec \nabla \phi_1||\vec \nabla \phi_2|\cos \theta\)

\(\Rightarrow \cos\theta = \frac{\vec \Delta \phi_1.\vec \nabla\phi_2}{|\vec \nabla \phi_1||\vec \nabla.\phi_2|}\)

\(=\frac{(4\hat i-2\hat j-\hat k)(4\hat i-2\hat j+4\hat k)}{|4\hat i-2\hat j-\hat k||4\hat i-2\hat j+4\hat k|}\)

\(=\frac{16+4-4}{\sqrt{16+4+1}\sqrt{16+4+16}}\)    \(\Big(\because \hat i.\hat i=\hat j.\hat j=\hat k.\hat k=1\) & \(\hat i.\hat j=\hat i.\hat k=\hat j.\hat k=0\Big)\)

\(=\frac{16}{\sqrt{21}\sqrt{36}}=\frac{16}{6\sqrt{21}}=\frac{8}{3\sqrt{21}}\)

\(\Rightarrow \theta =\cos^{-1}\left(\frac{8}{3\sqrt{21}}\right)\)

Hence, angle between given surfaces is \(\cos^{-1}\frac{8}{3\sqrt{21}}\).

35.

Solve for x and y : 2x + y = 7, 4x – 3y + 1 = 0

Answer»

2x + y = 7          ... (1) 

And 4x – 3y + 1 = 0 

⇒ 4x – 3y = –1     ... (2) 

Now, multiplying equation (1) by 2, we get 

4x + 2y = 14 ... (3) 

Now subtracting equation (2) from (3), we get 

4x + 2y – (4x – 3y) = 14 – (–1) 

⇒ 5y = 15 ⇒ y = 3. 

Now, putting y = 3 in equation (1), we get 

2x + 3 = 7 

⇒ 2x = 7 – 3 = 4 

⇒ x = 4/2 = 2. 

Hence, the solution of given system of equations is x = 2 and y = 3.

36.

\(\frac{2\times 4 \times 8 \times 16}{(log_24)^2 (log_48)^2(log _816)^4}\) = ?

Answer»

Calculation:

\(\frac{2\times 4 \times 8 \times 16}{(log_24)^2 (log_48)^2(log _816)^4}\)

⇒ \(\frac{{2{\rm{\;}} \times 4 \times 8 \times 16}}{{{{({\rm{lo}}{{\rm{g}}_2}4{\rm{\;}} \times {\rm{\;lo}}{{\rm{g}}_4}8{\rm{\;}} \times {\rm{lo}}{{\rm{g}}_8}16)}^2}{\rm{\;}} \times \left( {{\rm{lo}}{{\rm{g}}_4}8 \times {\rm{lo}}{{\rm{g}}_8}16} \right) \times {\rm{lo}}{{\rm{g}}_8}16}}\)

We know \(lo{g_{b\;}}a = \frac{{loga}}{{logb}}\)

⇒ \(\frac{{\left( {2 \times 4 \times 8 \times 16} \right)}}{{{{(\frac{{{\bf{log}}4}}{{{\bf{log}}2}} \times \frac{{{\bf{log}}8}}{{{\bf{log}}4}} \times \frac{{{\bf{log}}16}}{{{\bf{log}}8}})}^{2\;}} \times \left( {\frac{{{\bf{log}}8}}{{{\bf{log}}4}} \times \frac{{{\bf{log}}16}}{{{\bf{log}}8}}} \right) \times {\rm{lo}}{{\rm{g}}_8}16}}\)

⇒ \(\frac{{2\; \times 4 \times 8 \times 16}}{{{{(lo{g_2}16)}^2} \times \;{\rm{lo}}{{\rm{g}}_4}16 \times {\rm{lo}}{{\rm{g}}_8}16}}\)

⇒ \(\frac{{2\; \times 4 \times 8 \times 16}}{{{{(lo{g_2}{2^4})}^2} \times \;{\rm{lo}}{{\rm{g}}_4}{4^2} \times {\rm{lo}}{{\rm{g}}_8}\left( {8 \times 2} \right)}}\)

We know \(lo{g_{a\;}}a = 1\;\)

⇒ \(\frac{{2\; \times 4 \times 8 \times 16}}{{{{\left( 4 \right)}^2} \times 2 \times {\rm{lo}}{{\rm{g}}_8}\left( {8 \times 2} \right)}}\)

We know  \(\log \left( {m\; \times n} \right)\; = logm + logn\)

⇒ \(\frac{{2\; \times 4 \times 8 \times 16}}{{{{\left( 4 \right)}^2} \times 2 \times \left[ {{\rm{lo}}{{\rm{g}}_8}8 + {\rm{lo}}{{\rm{g}}_8}2} \right]}}\)

⇒ \(\frac{{2\; \times 4 \times 8 \times 16}}{{{{\left( 4 \right)}^2} \times 2 \times \left[ {1 + \frac{{{\rm{log}}2}}{{{\rm{log}}8}}} \right]}}\)

⇒ \(\frac{{2\; \times 4 \times 8 \times 16}}{{{{\left( 4 \right)}^2} \times 2 \times \left[ {1 + \frac{{{\rm{log}}2}}{{{\rm{log}}{2^3}}}} \right]}}\)

⇒ \(\frac{{2\; \times 4 \times 8 \times 16}}{{{{\left( 4 \right)}^2} \times 2 \times \left[ {1 + \frac{1}{3}} \right]}}\)

⇒ 24

 \(\frac{2\times 4 \times 8 \times 16}{(log_24)^2 (log_48)^2(log _816)^4}\) is 24.

37.

Find the directional derivative of \(\phi\) = x2+2xy at (1,-1,3) in the direction of i+2j+2k.

Answer»

\(\phi = \mathrm x^2+2\mathrm xy \) at (1, –1, 3)

directional vector \(\vec p = \hat i+2\hat j+2\hat k\)

We know that direction derivative \(= \nabla\phi.\hat p = \nabla \phi\frac{\vec p}{|\vec p|}\)

Now, \(\nabla \phi = \nabla(\mathrm x^2+2\mathrm xy)\)

\(=\hat i \frac{\partial}{\partial \mathrm x}(\mathrm x^2+2\mathrm xy)\) \(+\hat j\frac{\partial}{\partial \mathrm x}(\mathrm x^2+2\mathrm xy)\) \(+\hat k\frac{\partial}{\partial z}(\mathrm x^2+2\mathrm xy)\)

\(=(2\mathrm x+2y)\hat i + 2\mathrm x\hat j\)

\((\nabla \phi)_{(1, -1, 3)}=(2-2)\hat i + 2\hat j=2\hat j\)

And \(\hat p = \frac{\vec p}{| \vec p|}\) \(=\frac{\hat i+2\hat j+2\hat k}{\sqrt{1^2+2^2+2^2}}\) \(=\frac{1}{3}(\hat i+2\hat j+2\hat k)\)

Now, directional derivative of \(\phi\) at (1, –1, 3) in the direction of vector p

\(=(\nabla \phi)_{(1, -1, 3)}\hat p \) \(=2\hat j.\left(\frac{1}{3}(\hat i+2\hat j+2\hat k)\right)\)

\(=\frac{4}{3}\)    \(\Big(\hat i.\hat j=\hat j.\hat k = 0\) but \(\hat j.\hat j =1\Big)\)

38.

If the line ` y cos alpha = x sin alpha +a cos alpha ` be a tangent to the circle `x^(2)+y^(2)=a^(2)`, thenA. `sin^2alpha=1`B. `cos^2alpha=1`C. `sin^2alpha=a^2`D. `cos^2alpha=a^2`

Answer» Correct Answer - D
Given , `y=xtan alpha+a`
Condition for tangency is `a^2=a^2(1+tan^2alpha)[because c^2=a^2(1+m^2)]`
`rArr sec^2alpha=1rArr cos^2=1`
39.

if `y=4x+3` is parallel to a tangent to the parabola `y^2=12x`, then its distance from the normal parallel to the given line isA. `(213)/(sqrt(17))`B. `(219)/(sqrt(17))`C. `(211)/(sqrt(17))`D. `(210)/(sqrt(17))`

Answer» Correct Answer - B
Given equation of parabola is `y^2=12x` ....(i)
On differenting both sides w.r.t. x, we get
`2y(dy)/(dx)=12rArr (dy)/(dx)=(6)/(y)`
Since , the noraml to the curve is parallel to the line `y=4x+3`
`therefore` Slope of normal curve = Slope of line
`rArr -(y)/(6)=4rArr y=-24`
From Eq.(i),`(-24)^2=12x`
`rArr 24xx24xx12x`
`rArr x=48`
`therefore` Normal point on a curve is `(48-24)`.
And distance from `(48,-24)` to the line `4x-y+3=0` is
`(4xx48+24+3)/(sqrt(4^2+1^2))=(219)/(sqrt(17))`
40.

The value of `lambda` for which the curve `(7x + 5)^2 + (7y + 3)^2 = lambda^2 (4x + 3y-24)^2` represents a parabola isA. `+-(6)/(5)`B. `+-(7)/(5)`C. `+-(1)/(5)`D. `+-(2)/(5)`

Answer» Correct Answer - B
Given curve is `(7x+5)^2+(7y+3)^2`
`=lambda^2(4x+3y-24y)^2`
`rArr 49x^2+25+70x+49y^2+9+42y`
`lambda^2(16x^2+9y^2+576+24xy-144y-192x)`
`rArr (49-16lambda^2)x^2+(39-9lambda^2)y^2+(70+192lambda^2)x+(42+144lambda^2)y-24lambda^2xy+(25-576lambda^2)=0`
On comparing with
`ax^2+2hxy+by^2+2gh+2fy+c=0` we get
`a=49-16lambda^2,b=(49-9lambda^2)`
`h=-12lambda^2`
Condition for parabola is `ab=h^2`
`therefore (49-16lambda^2)(49-9lambda^2)=(-12lambda^2)^2`
`rArr 2401-441lambda^2-784lambda^2+144lambda^4-144lambda^4=0`
`rArr 2401-1225lambda^2=0`
`rArr lambda^2=(2401)/(1225)rArr lambda^2=((49)^2)/((35)^2)`
`rArr lambda=+-(49)/(35)`
`therefore lambda=+-(7)/(5)`
41.

Show that the locus of the orthocenter of the triangles formed by the lines (1+p)x-py+p(1+p)=0, (1+q)x-qy+q(1+q)=0 and y=0 is a straight line.

Answer»

 Intersection point of y = 0 with first line is the point B(-p, 0)          

Intersection point of y = 0 with second line is the point A(-q, 0)          

Intersection point of the two lines is the point C(pq, (p + 1)(q + 1))         

 Altitude from C to AB is x = pq          

Altitude from B to AC is y = -q/1+q (x + p)          

On solving these two we get x = pq and y = -pq         

 => locus of orthocenter is x + y = 0.

42.

`lim_(n to oo) x^(2)sin(log_(e)sqrt(cos((pi)/(x))))` is less thenA. `0`B. `-(pi^(2))/(2)`C. `-(pi^(2))/(4)`D. `(pi^(2))/(8)`

Answer» Correct Answer - A::D
`underset(xtoinfty)lim(x^(2)sin(log_(e)sqrt(cos((pi)/(x)))))/(log_(e)sqrt(cos((pi)/(x)))).log_(e)sqrt(cos((pi)/(2x)))`
`=underset(xtoinfty)lim(x^(2))/(2)(log_(e)[1+(cos((pi)/(x))-1)])/((cos((pi)/(x))-1))(-sin^(2)((pi)/(2x)))`
`=-(pi^(2))/(4)`
43.

The capacitance of a parallel plate capacitor is `C` when the region between the plate has air. This region is now filled with a dielectric slab of dielectric constant `k.` The capacitor is connected to a cell of `emfE`, and the slab is taken outA. charge `EC_(0)(K-1)` flows through the cellB. energy `E^(2)C_(0)(K-1)` is absorbed by the cellC. the energy stored in the capacitor is reduced by `E^(2)C_(0)(K-1)`D. the external agent has to do `E^(2)(C_(0)(K-1)` amount of work to take out the slab.

Answer» Correct Answer - A::B
Initial charge on capacitor `= KC_(o) E`
Charge after removing slab `= C_(o)E`
Amount of charge flows through the cell
`=KC_(o)E-C_(o)E=C_(o)E(K-1)`
Energy absorbed by cell `= C_(0)E(K-1)E_(0)=C_(0)E^(2)(K-1)`
Initial energy stored in capacitor `= 1//2 kC_(0) E^(2)`
Final energy stored in capacitor `= 1//2 C_(0) E^(2)`
Energy reduces in capacitor by
`1//2C_(0)E^(2)(k-1)`
Work done by external agent `(1)/(2)E^(2)C_(0)(K-1)`.
44.

Find the word which is out of the logic list:A) kick off B) begin C) reveal D) commence

Answer»

Correct option is C) reveal

45.

Write the main ideologies put forward by Satyashodhak Samaj.

Answer»
  • Satyashodhak Samaj started by Jyotiba Phule opposed social evils and domination of priests.
  • Started educational institutions for backward classes.
46.

Identify the benefits of education.

Answer»
  • To bring about changes in society. 
  • To maintain unity.
47.

Find the synonym of words written in capitals.Maintenance A) heritage B) racket C) alimony D) extortion

Answer»

Correct option is C) alimony

48.

Find the synonym of words written in capitals.Sufficient A) fake B) unreal C) adequate D) rare

Answer»

Correct option is C) adequate

49.

Direction: Answer the following questions by selecting the most appropriate option.The second language classroom is a confluence of varied languages. Teachers should give their students1. adequate self-explanatory notes2. summaries and simplified versions of texts3. Worksheets with a variety of tasks while covering the syllabus4. Comfortable environments to develop requisite skills5.

Answer» Correct Answer - Option 4 : Comfortable environments to develop requisite skills

The second language classroom is a confluence of varied languages. Teachers should give their students comfortable environments to develop requisite skills. In Krashen’s words, children require ‘comprehensible input’ in the second language. ‘Comprehensible input’ refers to using language which children are capable of understanding, and at the same time holds challenges for them.

  • An important part of making this language comprehensible is providing it in natural, communicative situations that are meaningful to children, and this will help children in meeting the challenge. For example, if children in your class know some words in English, then ‘comprehensible input’ might mean using these words in sentences that are meaningful for them.
  • ‘Comprehensible input’ and a ‘natural and communication friendly environment’ play an important role in acquiring a second language.
  • In the second language, the teacher should provide a comfortable environment so that students can express themselves and learn the requisite skills such as listening, speaking, reading, and writing holistically.
  • Adequate self-explanatory notes, summaries, and simplified versions of texts and Worksheets with a variety of tasks while covering the syllabus focused on writing and reading skills only in a fragmented manner. As the second language classroom is a confluence of varied languages, these do not help students to relate and express themselves.
  • In the second language classroom, learning from authentic material and resources is a must.

Hence, we can conclude that The second language classroom is a confluence of varied languages. Teachers should give their students Comfortable environments to develop requisite skills.

50.

Direction: Answer the following questions by selecting the most appropriate option.The teacher’s cues for activities are given in the first language, in a second language class This ______ exploits the communicative potential of a given structure.1. sandwich approach2. communicative approach3. Bilingual technique4. structural technique5.

Answer» Correct Answer - Option 3 : Bilingual technique

The teacher’s cues for activities are given in the first language, in a second language class. This bilingual technique exploits the communicative potential of a given structure.

  • The students’ L1 by incorporating it into the lesson. It does this by using bilingual technique all or part of the L1 within L2.
  • C.J. Dodson (1967) was the proponent of the bilingual method. It is used for teaching a foreign language, and it is complementary to the audiovisual method. From the beginning, the sandwich approach is used to convey the meaning bilingually. The mother tongue is used for bilingual pattern drills.
  • The bilingual technique exploits the communicative potential of a given structure as Learners may rely more on their L1, and it can turn out to be a translation method. The student, unable to use the skills in target language, hence lose the motivation and communicative potential of a given structure.
  • Sandwich approach: this approach involves the use of a positive comment, followed by a negative, then closed off with another positive comment for constructive feedback.
  • The structural technique is a technique wherein the learner masters the pattern of a sentence. It is based on the assumptions that language can be best learned through a scientific selection and grading of the structures or patterns of sentences and vocabulary.
  • Communicative approach:. The communicative approach is based on the idea that learning a language successfully comes through having to communicate real meaning. This approach focus is on meaningful interaction rather than on making complete sentences and cues in the first language. It focuses on fluency but not accuracy.

Hence, we can conclude that the teacher’s cues for activities are given in the first language, in a second language class. This Bilingual technique exploits the communicative potential of a given structure.