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 sequence of perfect squares.

Answer»

Answer is 1, 4, 9, 16, 25, 36,

2.

Write the sequence starting from 1 and is added subsequently

Answer»

\(1,1\frac{1}{2},2,2\frac{1}{2},3,3\frac{1}{2},4,........\)

3.

Write the sequence of prime numbers.

Answer»

Answer is 2,3,5,7,11,13,17,

4.

Write the sequence of multiples of 3.

Answer»

Answer is 3,6,9,12,15,

5.

Show that 12n cannot end with the digit 0 or 5 for any natural number n.

Answer»

Solution: 

If the number 12n, for any natural number n, ends with the digit 0 or 5, then it is divisible by 5. That is, the prime factorization of 12n contains the prime 5. This is not possible because prime factorisation of 12n = (22 x 3)n = 22n x 3n; so the only primes in the factorisation of 12n are 2 and 3 and the uniqueness of the fundamental theorem of arithmetic guarantees that there are no other primes in the factorization of 12n. So, there is no natural number n for which 12n ends with the digit zero.

6.

The number of four digit numbers with distinct digits is :(a) 9x9C3(B) 9x9P3(C)10C3(d) 10p3

Answer»

(b) The thousandth place can be filled up in 9 ways with any one of the digits 1, 2, 3, ...., 9. After that the other three places can be filled up in 9P3 ways, with any one of the remaining 9 digits including zero. Hence, the number of four digit numbers with distinct digits = 9x9p3 .

7.

PVC is widely used to make pipes because:(a) Cost effective(b) Does not react to chemicals(c) Easily available(d) Easy to transport

Answer» The correct option is (b) Does not react to chemicals

For explanation I would say: PVC is resistant to attack by kerosene oil, acid and chemicals.  It is water proof too.  Hence it is widely used for pipe manufacture for carrying sewage and rain water.
8.

The number of ways in which one or more balls can be selected out of 10 white, 9 green and 7 blue balls is (a) 892 (b) 881 (c) 891 (d) 879 (e) None of these

Answer»

(d) The required number of ways
= (10 +1)(9 +1)(7 +1) -1 = 879.

9.

The number of all possible selections of one or more questions from 10 given questions, each question having one alternative is (a) 310 (b) 210 – 1 (c) 310 – 1 (d) 210 (e) None of these

Answer»

(c) Since each question can be selected in 3 ways, by selecting it or by selecting its alternative or by rejecting it. Thus, the total number of ways of dealing with 10 given questions is 310 including a way in which we reject all the questions.
Hence, the number of all possible selections is 310 – 1.

10.

Convert 750° into radians.

Answer»

750x . (π/180) = (25π/6)C

11.

Find the conjugate of i(2 + i).

Answer»

Conjugate i(2 + i) = 2i + i2 = -1 + 2i 

∴ conjugate Z̄ = -1 -2i.

12.

How many 6-digit numbers can be formed from the digits 0, 1, 3, 5, 7 and 9 which are divisible by 10 and no digit is repeated ?

Answer»

Let the six digit number be abcdef
'a' can take all values except 0 since it will not be a 6 digit number then. So this means it can take any of 5 values.
'b' can take one the remaining 5 digits.
'c' can take any of the remaining 4
Similarly 'd' can take 3, 'e' can take 2 and 5'f' can take 1 value

So this means the total numbers that can be formed are :
5*5*4*3*2*1 = 600

For the numbers divisible by 10:
The last digit should be always 0
In this case the total possibilities are: 5*4*3*2*1*1 = 120

13.

Mr. Amit can walk 8 km in 1 hour 20 minutes.(a) How far does he go in :(i) 10 minutes ?(ii) 30 seconds ?(b) How long will it take him to walk :(i) 2500 m ?(ii) 6.5 km

Answer»

Amit walks 8 km in 1 hour 20 min

Or 1.1/3 = 4/3 hours

∴ Speed = Distance/Time

= 8/(4/3) = (8 × 3)/4 = 6 km/h

(a) (i) Distance covered in 10 minutes

= (6 × 1000 × 10)/ 60 = 1000 m = 1 km

(ii) Distance covered in 30 seconds

= (6 × 1000 × 30)/(60 × 60)  = 50 m

(b) (i) Time taken in 2500 m = 2500/(1000 × 6)

= 5/12 hours = 5/12 × 60 = 25 minutes

(ii) Time taken in 6.5 km

= 6.5/6 = 65/60 hours

= 1 hours 5 minutes

14.

∫sec22xdx =A. tan2x + kB. 2tan2x + kC. \(\frac{tan2x}{2}+k\)D. \(\frac{tanx}{2}+k\)

Answer»

Correct option is: C. \(\frac{tan2x}{2}+k\)

15.

The operation * is defined as a * b =2a+b, then (2 * 3) * 4 is -(a) 18 (b) 17 (c) 19 (d) 21

Answer»

Correct option (a) 18

16.

The operation * is defined as a * b = 2a + b then (2* 3) *4 is-(a) 18 (b) 17 (c) 19 (d) 21 

Answer»

Answer is (b) 17

17.

(d/dx) [sin-1 x + cos-1 x] = ?(a) 0(b) 1/√(1 - x2)(c) -1/√(1 - x2) (d) (1/2) √(1 - x2)

Answer»

Answer is (a) 0

18.

The modulus of the vector 19 i + 5 i -6k is -(a) √322 (b) √420 (c) √421 (d) √422

Answer»

Option: (d) √422

19.

The position vector of the point (x, y, z) is -

Answer»

Correct option:(D)

20.

Vector (a x a) . b=?(a) 1 (b) -1 (c) 2 (d) 0

Answer»

Correct option(d) 0

21.

sin-1 (1/x)(a) sec-1 x(b) cosec-1 x(c) tan-1 x(d) sin x

Answer»

Answer is (b) cosec-1 x

22.

Evaluate: lim(x→0) sinax/bx

Answer»

lim(x0) = sinax/ax .a/b = a/b

23.

Find k for which f(x) = {(k + x, x = 1), (4x + 3, x ≠ 1) is continuous at x = 1.

Answer»

lim(x1) f(x) = f(1)  lim(x1) 4x + 3 = k + 1

⇒ 4 + 3 = k + 1 ⇒ k = 6

24.

Show that the function f(x) = \(\begin{cases}(1 + 3x)^\frac{1}{2} ; x \neq0\\e^3 ; x = 0\end{cases}\) is continuous at x = 0.

Answer»

\(\lim\limits_{x \to 0} f(x) = \lim\limits_{x \to 0} (1 + 3x)^\frac{1}{3} = e^3 = f(0)\)

∴ f(x) is continuous at x = 0

25.

If A = [(α,0),(1,1,)], B = [(1,0),(5,1)], where A2 = B, then the value of α is(a) 1(b) -1(c) 4(d) No real value of α

Answer»

Answer is (a) 1

26.

What are meiocytes?

Answer»

Gamete mother cells/cells which undergo meiosis to form gametes.

27.

The maximum value of (1/x)2x^2 is (a) 1(b) e(c) e1/e(d) None of these

Answer»

Answer is (c) e1/e

28.

Define parthenogenesis.

Answer»

Development of the egg into a individual without fertilization.

29.

The normal to a given curve is parallel to x-axis if(a) (dy/dx) = 1(b) (dy/dx) = 1(b) (dy/dx) = 0(d) (dy/dx) = 1

Answer»

Answer is (a) (dy/dx) = 1

30.

Differentiate between binary fission and multiple fission.

Answer»

Binary Fission :
(i) Nucleus divides into two parts. 

(ii) It occurs during normal conditions. 

(iii) It gives rise to two individuals. 

(iv) Cytoplasm divides after each nuclear division.

(v) Includes definite pattern of division.
e.g., Amoeba.
Multiple Fission :
(i) Nucleus divides into many parts. 

(ii) It takes place during unfavourable conditions (Encysted stage), 

(iii) It forms many individuals. 

(iv) Cytoplasm does not divide after every nuciear division.

(v) Has no definite pattern of division.
e.g., Plasmodium.

31.

2tan-1 (1/3) + tan-1 (1/7) = (a) tan-1 (44/29)(b) π/2(c) 0(d) π/4

Answer»

Answer is (d) π/4

32.

If cosα, cosβ, cosγ are d.c.'s of a line, then the value of sin2α + sin2β + sin2γ is equal to which of the following ?(A) 1 (B) 2 (C) 3 (D) 4

Answer»

Correct option:

(B) 2 

33.

If (i, j, k) are three perpendicular unit vector, then the value of i · (j × k) + j · (i × k) + k (i × j) is which of the following ?(A) 0 (B) –1 (C) 1(D) 3

Answer»

Correct option:

(C) 1

34.

If y = log x3, the dy/dx =(a) 1 (b) log x (c) log (ex) (d) None of these

Answer»

Answer is (c) log (ex)

35.

The differential equation corresponding to the curve y = a sin px + b cos px is(a) y" + py = 0(b) y" + p2y = 0(c) y" - py = 0(d) y" - p2y = 0

Answer»

Answer is (a) y" + py = 0

36.

Integrating factor of differential equation (dy/dx) + Py = Q, where P and Q are functions of x is(a) ∫eP dx (b) e ∫Pdx(c) e -∫Pdx(d) None of these

Answer»

Answer is (a) ePdx

37.

∫|x| dx for x ∈ [-2,2] = (a) 0(b) 2(c) 1(d) 4

Answer»

Answer is (d) 4

38.

The four vertices of a quadrilateral are (1,2), (-5,6), (7, -4) and (k, -2) taken in order. If the area of the quadrilateral is zero, find the value of k

Answer» K=11

Because if area of the quadrilateral is zero then all the points lie on the same line .

Step1. Find equation of line with the help of given points .

Step1. Put point (k,-2)

Step3. Solve it for k.
39.

Find a point on x-axis equidistant from A and B.

Answer»

Let (x, 0) be a point on the x axis which is at equal distance from A and B.

(2 – x)2 + (3 – 0)2 = (5 – x)2 + (4 – 0)2

(2 – x)2 + 9 = (5 – x)2 + 16

(2 – x)2 + (5 – x)2 = 16 – 9

4 – 4x + x2 – 25 + 10x – x2 = 7

6x = 28

x = \(\frac{28}{6}=\frac{14}{3}\)

∴ Point on x axis is \((\frac{14}{3},0)\)

40.

If P, Q, R, S are the midpoints of the sides write the coordinates of P, Q, R, S

Answer»

\(P=(\frac{3+7}{2},7)=(5,7)\)

\(Q=(7,\frac{9+7}{2})=(7,8)\)

\(R=(\frac{3+7}{2},9)=(5,9)\)

\(S=(3,\frac{9+7}{2})=(3,8)\)

41.

Calculate the sides of PQRS.

Answer»

PQ = \(\sqrt{(7-5)^2+(8-7)^2}\) = \(\sqrt{2^2+1^2}\) = \(\sqrt{5}\)

QR = \(\sqrt{(5-5)^2+(9-8)^2}\) = \(\sqrt{(-2)^2+1^2}\) = \(\sqrt{5}\)

RS = \(\sqrt{(3-5)^2+(8-9)^2}\) = \(\sqrt{(-2)^2+(1)^2}\) = \(\sqrt{5}\)

SP = \(\sqrt{(5-3)^2+(7-8)^2}\) = \(\sqrt{2^2+1^2}\) = \(\sqrt{5}\)

42.

Prove that P(4,5) the point on AC and BD.

Answer»

AP = \(\sqrt{(4-2)^2+(5-3)^2}=2\sqrt{2}\)

PC = \(\sqrt{(6-4)^2+(7-5)^2}=2\sqrt{2}\)

AP + PC = 4√2 = AC

∴ P (4, 5) is a point on AC .

BP = \(\sqrt{(4-5)^2+(5-4)^2}=\sqrt{2}\)

PD = \(\sqrt{(3-4)^2+(6-5)^2}=\sqrt{2}\)

BP + PD = √2 + √2 = 2√2 = BD

∴ P (4, 5) is also a point on BD.

43.

Write the coordinates of the midpoints of BC.

Answer»

Midpoints of BC = \((6,\frac{5+1}{2})\) = (6,3)

44.

Calculate the area of the rectangle ABCD

Answer»

Area of the rectangle ABCD = AB × BC 

= 4 × 2 

= 8 m2

45.

Write the coordinates of the midpoints of AC.

Answer»

Midpoints of AC = \((\frac{2+6}{2},\frac{1+5}{2})\) = (4,3)

46.

Suggest a name suitable to PQRS

Answer»

Rhombus (SQ = 4, RP = 2, diagonals are not equal, sides are equal hence it is a rhombus)

47.

Check whether AC = BD or not.

Answer»

AC = \(\sqrt{(6-2)^2+(7-3)^2}\) = \(\sqrt{35}\) = \(4\sqrt2{}\)

BD = \(\sqrt{(3-5)^2+(6-4)^2}\) = \(\sqrt{8}\) = \(2\sqrt2{}\)

AC ≠ BD

48.

Find the lengths of AB and BC.

Answer»

AB = |7 – 3| = 4 BC = |9 – 7| = 2

49.

A (6, 0) is a point on a circle with centre (0,0). Find the radius of the circle.

Answer»

Radius of the circle = 6

50.

Find the coordinates of a point on the x - axis which is at a distance of 5 units from (4, -5). Find the coordinates on the y-axis

Answer»

The point on x-axis which is at a distance of 5 units from (4,-5) is (4, 0).

(x – 4)2 + 52 = 25,

∴ x = 4

Point on x axis is (4, 0)

Point on y axis is (0, y).

(0 – 4)2 + (y + 5)2 = 25,

∴ y = –8, –2

The point on y -axis which is at a distance of 5 units from (4, –5) are (0, –2), (0, –8)