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.

Please give me a list of Bronsted- Lowry  and Lewis acids and bases with explanation of how to distinguish between them.

Answer»

Bronsted-Lowry Acid

A Bronsted-Lowry acid, like an Arrhenius acid, is a compound that breaks down to give an H+ in solution.

Bronsted-Lowry Base

The Bronsted-Lowry base refers to any atom or ion capable of accepting or bonding to a free proton in solution.

examples include:

  • Methanol – CH3OH
  • Formaldehyde – H2CO
  • And water – H2O

Lewis Acid

A Lewis acid refers to an atom or molecule that accepts an electron pair. 

Lewis Acid Examples in Organic Chemistry

  • Borane – BH3 (hydroboration reaction)
  • Aluminum Chloride – AlCl3 (electrophilic aromatic substitution reaction)
  • Iron (III) Bromide – FeCl3 (electrophilic aromatic substitution reaction)
  • and H+

Lewis Base

Since the Lewis definition has to do with the transfer of electrons, a Lewis Base is an electron pair donor. 

  • A Lewis acid is an electron pair acceptor.

  • A Lewis base is an electron pair donor.

2.

The value of `cos^(-1)(cos(2tan^(-1)((sqrt(3)+1)/(sqrt(4-2sqrt(3))))))`isA. `(pi)/6`B. `(5pi)/6`C. `(5pi)/12`D. `(pi)/12`

Answer» Correct Answer - B
`(sqrt(3)+1)/(sqrt(4-2sqrt(3)))=(sqrt(3)+1)/((sqrt(3)-1))=(sqrt(3)+1)/(sqrt(3)-1)=2+sqrt(3)="tan"(5pi)/12`
`:.cos^(-1)(cos(2.(5pi)/12))=cos^(-1)(cos(5pi)/6)=(5pi)/6`
3.

`sum_(r=1)^(n) 1/(log_(2^(r))4)` is equal toA. `(n(n+1))/2`B. `(n(n+1)(2n+1))/12`C. `1/(n(n+1))`D. `(n(n+1))/4`

Answer» Correct Answer - D
`sum_(r=1)^(n)1/(log_(2^(t))4)1/(1/rlog_(2)^(4))=r/2`
`sum_(r=1)^(n) r/2=1/2(1+2+3+……+n)=(n(n+1))/4`
4.

In how many types ways can five different examination papers of maths, physics, chemistry, computer an physical education be arranged so that physics and chemistry papers never come together.A. `54`B. `120`C. `48`D. `72`

Answer» Correct Answer - D
Total arrangement of papers are `=5!=120` when physics and chemistry come together `=4!xx2!=48`. Hence,
Required number of ways are `=120-48=72`
5.

The maximum product of two positive numbers, when their sum of the squares is 200, is ________. (a) 100 (b) 25√7(c) 28 (d) 24√14

Answer»

The correct answer is : (a) 100

6.

If \(\vec {a}\) x (\(\vec {b}\) x \(\vec {c}\)) = (\(\vec {a}\) x \(\vec {b}\)) x \(\vec {c}\) for non-coplanar \(\vec {a}\), \(\vec {b}\), \(\vec {c}\) then ________.(a) \(\vec {a}\) parallel to \(\vec {b}\)(b) \(\vec {b}\) parallel to \(\vec {b}\)(c) \(\vec {c}\) parallel to \(\vec {a}\)(d) \(\vec {a}\)  + \(\vec {b}\) + \(\vec {c}\) = \(\vec {0}\)

Answer»

 (c) \(\vec {c}\) parallel to \(\vec {a}\)

7.

{2,4,8} = {2,4,4,8,8,2} are equal sets or not, if yes then how?

Answer»

{2,4,4,8,8,2} = {2,4,8}

Because if set elements are repeated then if written one time in roster from of set.

so given sets are equal.

8.

Let \( f(x)=\sqrt{x-2}+\sqrt{x+47-14 \sqrt{x-2}} \) be a real valued function for \( x \geq 2 \), then the value of \( f(50)+f(66) \) is equal to

Answer»

f(x) = \(\sqrt{x-2}\) + \(\sqrt{x+47-14\sqrt{x-2}}\) ; x \(\geq\) 2

∴ f(50) = \(\sqrt{48}\) + \(\sqrt{50+47-14\times4\sqrt3}\)

 = 4\(\sqrt3+\sqrt{97-56\sqrt3}\)

f(66) = \(\sqrt{64}+\sqrt{66+47-14\sqrt{64}}\)

 = 8 + \(\sqrt{113-112}\)

 = 8 + 1

 = 9

∴ f(50) + f(66) = 4\(\sqrt3+\sqrt{97-56\sqrt3}+9\)

9.

In the experiment of throwing a die, consider the following events : A = {1, 3, 5}, B = {2, 4}, C = {6} Are these events mutually exclusive?

Answer»

Since the happening of one of the given events A, B, C prevents the happening of other two, hence the given events are mutually exclusive.

Otherwise A ∩ B = ϕ, B ∩ C = ϕ, C ∩ A = ϕ

Hence they are mutually exclusive events.

10.

The graph of \( y=9^{x} \) and \( y=\log _{9} x \) is are mirror image of each other about line y = x prove.

Answer»

Let y = 9x

The mirror function of y = 9x about line y = x will find by inter changing x & y. i.e., putting x in place of y & y in place of x.

So, x = 9y

⇒ y = log9x   (By taking log9 on both sides)

Hence, functions y = 9x & y = log9x are mirror images of each other about line y = x.

11.

If two sets A and B have 99 elements in common, then the number of elements common to each of the sets A×B and B×A are

Answer»

To find A × B we take one element from set A and one from set B. 

Given that 99 elements are common to both set A and set B.

Suppose these common elements are N1​, N2​, N3​,... N99​.

Select an ordered pair for A×B such that both are selected out of these common elements.

Examples: (N1​,N2​),(N3​,N5​)

All these will also be elements of B × A. 

Hence number of elements common to A × B and B × A is 99 × 99 = 992 ( first element in ordered pair can be selected in 99 ways; second element can also be selected in 99 ways)

n[(A×B)∩(B×A)] = n[(A∩B)∩(B∩A)] = (99)(99) = 992

12.

Solve the in equation √(x + 2) > √(8 − x2).

Answer»

When a, b ∈ R and a ≥ 0, b ≥ 0 then √a > √b

⇔ a > b ≥ 0

∴ √(x + 2) > √(8 - x2)

⇔ x + 2 > 8 – x2 ≥ 0 and x > –2, |x| < 2√2

We have (x + 2) > 8 – x2

⇔ x2 + x – 6 > 0

⇔ (x + 3) (x – 2) > 0

⇔ x ∈ (– ∞, – 3) ∪ (2, ∞)

We have 8 – x2 ≥ 0

⇔ x2 ≤ 8 ⇔ |x| < 2√2

⇔ x ∈ [–2√2 , 2√2]

Also x + 2 > 0 ⇔ x > – 2

Hence x + 2 > 8 – x2 ≥ 0

⇔ x ε ((– ∞, –3) ∪ (2, ∞)) ∩ [–2√2 , 2√2] and x > –2

⇔ x ∈ (2, 2√2)

The solution set is [x ∈ R : –2 < x ≤ 2√2]

13.

\( y=(x)^{\wedge} 1 / x \) has maxima at \( x=? \)

Answer»
differentiate y and put dy/dx=0 
We get x=e as critical pt.
now by checking sign scheme of dy/dx at x=e we get x= e as point of Maxima. Hence x=e is the answer.


14.

\text { If } y=(1+x)\left(1+x^{2}\right)\left(1+x^{4}\right) \ldots .\left(1+x^{2 n}\right) \text { then the value of }\left(\frac{d y}{d x}\right) \text { at } x=0 \text { is }\(\text { If } y=(1+x)\left(1+x^{2}\right)\left(1+x^{4}\right) \ldots .\left(1+x^{2 n}\right) \text { then the value of }\left(\frac{d y}{d x}\right) \text { at } x=0 \text { is }\)

Answer»

y=(1+x)(1+x2)(1+x4)......(1+x2n)

⇒log y =Iog (1+x)+ Iog (1+x2) ......+ Iog (1+x2n)
1/y. dy/dx= 1/(1+x )+ 2x/(1+x)......+ 2nx2n−1/(1+x2n)

⇒dy/dx= y.(1/1+x + 2x/1+x2.......+ 2nx2n−1/1+x2n)
Substitute the value x=0,
⇒∣dy/dx∣x=0 =1.1 =
1

15.

\(\text { If } y=(1+x)\left(1+x^{2}\right)\left(1+x^{4}\right) \ldots .\left(1+x^{2 n}\right) \text { then the value of }\left(\frac{d y}{d x}\right) \text { at } x=0 \text { is }\)

Answer»

log y = log(1 + x) (1 + x2) (1 + x4).....(1 + x2n)

log y = log(1 + x) + log(1 + x2) + log(1 + x4) + ....+log(1 + x2n)

\(\frac1y\frac{dy}{dx} = \frac1{1+x}+\frac{2x}{1+x^2} + \frac{4x^3}{1+x^4}+....+\frac{2n x^{2n-1}}{1+x^{2n}}\) 

y at x = 0 is y(0) = 1

\(\therefore\) \(\frac{dy}{dx}\) at x = 0

\(\therefore\) (\(\frac{dy}{dx}\))(x = 0) = y(0)(\(\frac1{1+0}+\frac{2\times0}{1+0}+\frac{4\times0}{1+0}\).....+\(\frac{2n-0}{1+0}\))

 = 1( 1 + 0 + 0 + .... + 0) = 1

16.

Suggest at least one method of creating something useful or beautiful from waste.

Answer»
  1. Used plastic bottles can be used as pots for plants. This would reduce waste and add beauty to the surroundings.
  2. Used coconut shells can be used for craft to make musical instruments like the tabla, etc.
  3. Pista shells can be used to fill in drawings adding beauty to the drawing.
17.

In the given figure, why AC||DE?

Answer»

In the given figure,

AC || DE because if we take DC as a transversal then angle ACD = angle CDE

But they are alternate angles,

Hence AC || DE

 ∵ ∠ EDC = 100° and ∠DCA are alternative interior angles of lines DE and AC whose transversal is CD.

∴ DE || AC (One pair of alternative angles are equal . so lines are parallel).

18.

In ABC, angle A=76,angle B=48,angle C= ??

Answer»

In any triangle, sum of angles is 180°.

\(\therefore \angle A + \angle B+ \angle C = 180° \)

⇒ \(\angle C = 180° - \angle A - \angle B\)

\(= 180° - 76° - 48° \)

\(= 180° - 124° \)

\(= 56 ° \)

19.

Which of the following is the formula for area of a circle?(a) πr(b) 2πr(c)  πr2(d) 2πr2

Answer» Option (c) πr^2

The correct option is: (c)  πr2

20.

16 8 12 30 105 ?

Answer»

Solution:

As the question is 16, 8, 12, 30, 105

also written as 24, 23 , 22x3, 2x3x5, 3x5x7, 

As the power of 2 started ending and finally diminished and multiplication of prime number started.

So the next term must be 5x7x11 = 385

21.

Which of the following is the value of cosec2θ -cot2θ(a) 1 (b) 2(c) √2(d) 1/2

Answer»

The value of cosec2θ -cot2θ = 1 

22.

Fill in the blanks :-The common difference of A.P. 5, 9, 13, 17 is ................

Answer»

The common difference of A.P. 5, 9, 13, 17 is 1/3.

Common difference is 4
23.

Fill in the blanks :-The value of sin 60°cos30° – sin30°cos60° is ...............

Answer»

The value of sin 60°cos30° – sin30°cos60° is 1/2.

24.

H.C.F. and L.C.M. of two numbers are 25 and 50 respectively. Which of the following is the product of the numbers ?(a) 1050 (b) 1150 (c) 1250 (d) 1350

Answer»

H.C.F. and L.C.M. of two numbers are 25 and 50 respectively. Which of the following is the product of the numbers 1250 

25.

Which of the following is a rational number.(a) √(3/21)(b) √(16/32)(c) √(81/91)(d) √(49/64)  

Answer»

Which of the following is a rational number.√(49/64)  

26.

Which of the following is a solution of the quadratic equation 2x2 + x – 6 = 0?(a) x = 2(b) x = 3/2(c) x = -3(d) x = 3

Answer»

The following is a solution of the quadratic equation 2x2 + x – 6 = 0 x = 3/2

27.

Centroid of a triangle divides its median in which of the following ratio?(a) 1 : 2 (b) 2 : 1 (c) 1 : 3 (d) 3 : 1

Answer»

Centroid of a triangle divides its median in which of the following ratio 2 : 1 

28.

The value of ∫(ax3 + bx + c) dx , x ∈ [-2, 2] depends on(A) The value of a (B) The value of b (C) The value of c (D) None of these

Answer»

(C) The value of c 

29.

The order and degree of the differential equation d4y/dx4 = y + (dy/dx)4 are respectively(A) 2,2 (B) 4,1 (C) 2,4 (D) 4,2

Answer»

Correct option:

(B) 4,1 

30.

Which of the following is not equivalent to `p to q`.A. p only if qB. q is necessary for pC. q only if PD. p is sufficient for q

Answer» Correct Answer - C
`ptoq` means
(i) p is sufficient for q
(ii) p only if q
(iii) q is necessary conditions for p
(iv) `~qto~p`
31.

The general solution of the differential equation of all circles having centre at A(-1, 2) is ..... .A. `x^(2)+y^(2)+x-2y+c=0`B. `x^(2)+y^(2)-2x+4y+c=0`C. `x^(2)+y^(2)-x+2y+c=0`D. `x^(2)+y^(2)+2x-4y+c=0`

Answer» Correct Answer - D
General equation of a circle with centre (-g,-f) is
`x^(2)+y^(2)+2gx+2fy+c=0` ltbr gt If `(-g,-f)=A(-1,2)`
Then equation of circle,
`x^(2)+y^(2)+2x-4y+c=0`
32.

The value of `int_(-3)^(3)(ax^()+bx^(3)+cx+k)dx`, where a,b,c,k are constants, depends only on. . . .A. a, b and cB. kC. a and bD. and k

Answer» Correct Answer - B
Let f(x)`=ax^(5)+bx^(3)+cx`
`rArrf(-x)=-ax^(5)-bx^(3)-cx=-f(x)`
`rArr`f(x) is an odd function .
`therefore_(-3)^(3)(ax^(5)+bx^(3)+cx)dx=0`
`thereforeint_(-3)^(3)(ax^(5)+bx^(3)+cx+k)dx` is depends only k.
33.

A function f is defined by f(x) = 2x – 5 write the value of (i) f(7) (ii) f(-3)

Answer»

Given f(x) = 2x – 5 

∴ (i) f(7) = 2(7) – 5 = 9. 

(ii) f(-3) = 2(-3) – 5 = -11.

34.

Find the slope of the joining the points (3, 2) and (-1, 4)

Answer»

Slope of the line = m 

= (y2 - y1)/(x2 - x1

= (4 - 2)/(-1 - 3) 

= 2/-4 

= -1/2

35.

If X and Y are two sets such that X ∪ Y has 50 elements, X has 28 elements, Y has 32 elements, how many elements does X ∩ Y have?

Answer»

n(x ∪ y) = n(x) + (n ∪ y) – n(x ∩ y)

50 = 28 + 32 (x ∩ y) ⇒ [∴ n(X ∩ Y) = 10]

36.

Let A = {1,2,3,4,5,6} and B = {2,4,6,8}, Find A – B and B – A.

Answer»

A – B = {1,3,5), (B – A) = {8}

37.

The sample space of four coins tossed together is:1. 82. 643. 324. 16

Answer» Correct Answer - Option 4 : 16
  • The sample space of four coins tossed together is 16.
  • Each coin toss has 2 possible outcomes, i.e. H or T.
  • So the flipping of 4 coins has 2x2x2x2 = 16 possible outcomes.
38.

Two coins are tossed. Find a sample space.

Answer»

Sample space = {HH, HT,TT,TH}

39.

Write the negation of ” √2 is not a complex number.”

Answer»

~(√2 is not a complex no.) = √2 is a complex no.” 

40.

Find the number whose 8 times is 8 less than 40.1. 22. 33. 44. 5

Answer» Correct Answer - Option 3 : 4

Calculation:

Let the number be x

According to question,

8x = 40 – 8

⇒ 8x = 32

⇒ x = 4

∴ The required number is 4
41.

Which of the following is not an irrational number?1. √22. √33. √44. π

Answer» Correct Answer - Option 3 : √4

Concept used:

Irrational numbers are those numbers which have decimal expansion that neither terminating nor repeating.

Calculation:

Like π = 3.1415926…….

√2 = 1.41421….

√3 = 1.73205……

But √4 = 2

∴ √4 is not an irrational number
42.

By which least number should 71232 be multipled so that the resultant number is a perfect square?1. 12312. 11133. 12344. 3411

Answer» Correct Answer - Option 2 : 1113

Concept used:

For a number to be a perfect square, each prime factor has to be paired.

Calculation:

71232 = 2 × 2 × 2 × 2 × 2 × 2 × 3 × 7 × 53

The factors 3, 7 and 53 are not paired.

Hence, 71232 must be multiplied by 1113 i.e. (3 × 7 × 53) for it to be a perfect square

∴ The number should be multiplied by 1113
43.

If a number is divided by 3, the remainder will be 2. If the number is added by 5 and then divided by 3, then what will be the remainder?1. 12. 23. 04. 3

Answer» Correct Answer - Option 1 : 1

Given:

A number is divided by 3, the remainder will be 2

Calculation:

let the number be X

X = 3K + 2

According to question

X + 5 = 3K + 2 + 5

⇒X + 5 = 3K + 7

⇒X + 5 = 3K + 6 + 1

⇒X + 5 = 3(K + 2) + 1

Now,

3(K + 2) type number is definitely divisible by 3 so the remainder will be 1

44.

HCF of 88 and 220 is:1. 82. 223. 444. 11

Answer» Correct Answer - Option 3 : 44

Concept used:

HCF can be found by prime factorization method

HCF is the common factor of different numbers

Calculation:

88 = 2 × 2 × 2 × 11

220= 2 × 2 × 5 × 11

Common factor = 2 × 2 × 11

⇒ 44

∴ The HCF of 88 and 220 is 44

45.

Write one rational and one irrational number lying between `0.25` and `0.32`

Answer» Rational number = 0.30
Irrational number = `0.3010203040…`
Or any other correct rational and irrational number
46.

Give two rational numbers lying between 0.232332333233332... and 0.212112111211112.

Answer»

Let 

a = 0.232332333233332...

b = 0.212112111211112...

Here the decimal representation of a and b are non-terminating and non-repeating. So we observe that in first decimal place of a and b have the same digit 2 but digit in the second place of their decimal representation are distinct. And the number a has 3 and b has 1. So a > b.

Hence two rational numbers are 0.222, 0.221 lying between 0.232332333233332... and 0.212112111211112...

47.

किसी धनराशि पर 4 % वार्षिक दर से 2 वर्षा का साधरण ब्याज रुपए 80 है | उसी धनराशि ब्याज किंतना होगी -A. Rs. 82.60B. Rs. 82.20C. Rs. 81.80D. Rs. 81.60

Answer» Correct Answer - d
(d) Rate% = 4%, Time `(t_(1))` = 2 years
SI for 2 years `= 4 xx 2 = 8%`
CI for 2 years ` = 4 + 4 + (4+4)/(100) `
= 8.16%
Required CI ` = (80)/(8)xx 8.16`
= Rs. 81.6
48.

निश्चित ब्याज की दर से, किसी धनराशि पर 1 वर्ष का साधरण ब्याज रूपए 260 है उसी राशि पर दो वर्ष का चक्रवृद्धि ब्याज रूपए 540 . 80 है | तो ब्याज की दर वार्षिक हैA. 0.04B. 0.06C. 0.08D. 0.1

Answer» Correct Answer - c
(c) SI for 1 years = Rs. 260
SI for 2 years `= 260 xx 2 = Rs. 520`
Difference in (CI - SI)
(540.80 - 520) = Rs. 20.8
Requried Rate% `= (20.8)/(260)xx 100 = 8%`
49.

Number of solution of \( \cos x=1-\frac{x}{5} \) is

Answer»

total 5 number of solutions i got this answer by drowning graph

50.

HCF of 105,154

Answer»

Factor of 105 = 3*5*7

Factor of 154 = 2*7*11

HCF = 7