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.

From the following identify the vector quantities:Pressure, temperature, energy, time, gravitational potential, power, total path length, charge, coefficient of friction, impulse.

Answer»

Vector quantity: Impulse.

2.

A boy has 3 red, 4 green and 4 blue marbles in his pocket. How many will he have to take out of his pocket to ensure that he has taken out at least one of each color?

Answer»

3 red  4 blue, 4 green  add them up and it is 11  the first three times you might pull out all red so u have one color so your down to blue and green the next for times you pull out all blues so that is a total of 7 Tries add 1 there is only green in your pocket now so it is  8  it can be 9 also it matters what the first color is

3.

A is five times as efficient as B. A can complete a work in 60 days less than B. If both of them work together then in how many days the work would be completed?1. 10.5 days2. 11.5 days3. 12 days4. 12.5 days

Answer» Correct Answer - Option 4 : 12.5 days

Given:

The efficiency of A = 5 × the efficiency of B

Then ratio of efficiency of A to the efficiency of B = 5 : 1

A can complete a work in 60 days less than B.

Concept used:

Days is inversely proportional to efficiency

If A does a work in x days and B does a work in y days, the ratio of days = x : y and

The ratio of efficiency = y : x

If a person does a work in ‘n’ days then one day work by a person will be 1/n part of total work

Calculation:

Let the efficiency of A and B be 5x and x respectively.

Then the number of days taken by A and B for a work will be x and 5x respectively

A takes less time than B = 5x – x

⇒ A – B = 4x days

According to question, A – B = 60 days

⇒ 4x = 60

⇒ x = 60/4

⇒ x = 15

Then A takes days to complete a work = x

⇒ 15 days

Now one day work by A = 1/15

B takes days to complete a work = 5x

⇒ 5 × 15

⇒ 75 days

Now one day work by B = 1/75

One day work when both work together = one day work by A + one day work by B

⇒ 1/15 + 1/75

⇒ (5 + 1)/75

⇒ 6/75

⇒ 2/25

⇒ 1/12.5

Now, one work completed by both A and B = 12.5 days

The work would be completed by both in 12.5 days

4.

If A,G,H are arithmetic, geometric and harmonic mean between a and b. Then A, G,H are inA)ApB) GPC)HPD)NONE

Answer»

They are in GP 

Answer (B)  for two numbers a and b

A= (a+b)/2

G2= a.b

H= 2a.b/(a+b)

Thus A.H= a.b = G2

Shows A, G,H are in GP

5.

In the following number series, a wrong number is given. Find out the wrong number.9, 65, 219, 516, 10051. 92. 653. 2194. 10055. 516

Answer» Correct Answer - Option 2 : 65

The pattern of the given series can be explained as:

23 + 1 = 9

43 + 2 = 66 ≠ 65

63 + 3 = 219

83 + 4 = 516

103 + 5 = 1005

∴ The wrong number is 65.

6.

What is phasor diagram

Answer»

Phasor Diagrams are a graphical way of representing the magnitude and directional relationship between two or more alternating quantities. Sinusoidal waveforms of the same frequency can have a Phase Difference between themselves which represents the angular difference of the two sinusoidal waveforms.

7.

Give two examples of each: Law of Vector Addition, Dot Product and Cross Product from daily life.

Answer»
  • When a lawn mower is pushed, the mower moves along the grassy ground but the force is applied at an angle to the direction in which the mower moves.
  • Opening or close a tap, or for that matter where a turning moment is produced, are examples of the cross product of two vectors.
  • Opening/closing a tap, we apply equal and opposite forces at the two diametrically opposite ends of the tap. These force produce a turning couple which turns the tap.
  • The turning moment of the couple is equal to r × f, where r= diametet of the tap head, at two ends of which force f is applied.
  • Same is true of when we put or take out a screw.
  • When a door is opened/closed the angular momentum it has is equal to r × p, where p is the linear momentum of the free end of the door being opened/closed, and r is the perpendicular distance from the hinges on which the door rotates and the free end of the door.
8.

Two consecutive number p,p + 1 are removed from natural numbers. 1,2,3, 4……….., `n-1,` n such that arithmetic mean of these number reduces by 1, then (n-p) is equal to.A. `1`B. `2`C. `3`D. `4`

Answer» Correct Answer - A
`A.M`. of `1,2,3,4,…….,n`
`((n(n+1))/(2))/(n) = (n+1)/(2)`
If `p,p+1` are removed then
`A.M.=((n(n+1))/(2)-(2p+1))/(n-2)`
` therefore 1=((n+1)/(2))-((n(n+1)-2(2p+1))/(2.(n-2)))`
`implies(n-p)=1`
9.

Let `A,B,C` are `3` points on the complex plane represented by complex number `a,b,c` respectively such that `|a|= |b|= |c|=1,a+b+c = abc=1`, thenA. area of triangle `ABC` is `2` (square unit)B. triangle `ABC` is an equilateral triangleC. traingle `ABC` is right isosceles triangle.D. orthocentre of traingle `ABC` lies outside the triangle

Answer» Correct Answer - C
`bar(a)+bar(b)+bar(c )=1`
`implies ab+bc+ca = 1`
implies a,b,c are roots of cubic
`z^(3)-z^(2)+z-1=0`
`(z^(2)+1)(z-1)=0`
`implies z=pm i,1`
10.

Let `x,y,z in` C satisfy `|X| = 1,|y-6-8i| = 3 and |z + 1-7i| = 5` respectively, then the minimum value of `|x-z| + |y-z|` is equal toA. `1`B. `2`C. `5`D. `6`

Answer» Correct Answer - D
To find minimum valume of `|x-z| + |y-z|`, we know that
` |z_(1)+z_(2)| le |z_(1)|+ |z_(2)|" " AA z_(1),z_(2) in C`
`therefore |x-z|+|y-z|ge |(x-z)+(-y+z)|`
`implies E ge |x-y|`
Also, equality holds when x,y,z are collinear points.
`therefore |x-y|_(min) =c_(1)c_(2)-(r_(1)+r_(2))`
`10-(1+3)=10-4=6`
11.

If `M` is a `2xx2` matrix such that `[(1),(-1)]=[(-1),(2)]` and `M^(2)[(1),(-1)]=[(1),(0)]` then sum of elements of `M` isA. `0`B. `2`C. `5`D. `8`

Answer» Correct Answer - C
Let `M=[[a,b],[c,d]]`
Now, `M [[1],[-1]] = [[-1],[2]] & M^(2) [[1],[-1]]=[[1],[0]]`
`impliesa=-1,b=0, c=4,d=2`
`therefore (a+b+c+d) = 5`
12.

The lines x = a and y = b, are (a) intersecting(b) parallel(c) overlapping(d) (None of these)

Answer»

Correct answer is: (a) intersecting

Lines x=a is a line parallel to y axis and y=b is a line parallel to x axis. So they will intersect.

13.

Prime factors of the denominator of a rational number with the decimal expansion 44.123 are (a) 2,3(b) 2,3,5(c) 2,5(d) 3,5

Answer»

Correct answer is: (c) 2,5

Since it has a terminating decimal expansion,

so prime factors of the denominator will be 2,5

14.

Let `p,q,r` be roots of cubic `x^(3)+2X^(2)+3x+3=0`, thenA. `(p)/(p+1) + (q)/(q+1) + (r )/(r+1) = 5`B. `((p)/(p+1))^(3) + ((q)/(q+1))^(3) + ((r )/(r+1))^(3) = 45`C. `((p)/(p+1))+((q)/(q+1))+((r )/(r+1)) = 6`D. `((p)/(p+1))^(3)+((q)/(q+1))^(3)+((r )/(r+1))^(3)= 46`

Answer» Correct Answer - A
Using transformation, let
`((p)/(p+1)) = y implies p= ((y)/(1-y))`
As,p is root of cubic so
`y^(3)-5y^(2)+6y-3=0`
Now, `y_(1), y_(2),y_(3)` are roots of above equation so
` ((p)/(p+1)+(q)/(q+1)+(r )/(r+1))=5`
Also `Sigmay_(1)=5,Sigmay_(1)y_(2)=6, Sigmay_(1)y_(2)y_(3)=3`
`therefore y_(1)^(3)+y_(2)^(3)+y_(3)^(3)-3y_(1)y _(2)y_(3)`
`= Sigmay_(1)((Sigmay_(1))^(2)-3SigmaY_(1)y_(2))`
`implies y_(1)^(3)+y_(2)^(3)+y_(3)^(3)-3(3)=5((5)^(2)-3(6))`
`impliesy_(1)^(3)+y_(2)^(3)+y_(3)^(3)=44`
` therefore ((p)/(p+1))^(3)+((q)/(q+1))^(3)+((r)/(r+1))^(3)=44`
15.

Let `a_1,a_2,a_3.....` be an arithmetic progression and `b_1,b_2,b_3......` be a geometric progression. The sequence `c_1,c_2,c_3,....` is such that `c_n=a_n+b_n AA n in N.` Suppose `c_1=1.c_2=4.c_3=15 and c_4=2.` The common ratio of geometric progression is equal toA. -2B. -3C. 2D. 3

Answer» Correct Answer - A
16.

Let `a,b,c`, are non-zero real numbers such that `(1)/(a),(1)/(b),(1)/(c )` are in arithmetic progression and `a,b,-2c`, are in geometric progression, then which of the following statements (s) is (are) must be true?A. `a^(2),b^(2), 4c^(2)` are in geometric progressionB. `-2a,b, -2c` are in arithmetic progressionC. `a^(3)+b^(3)+c^(3) - 3abc = 0`D. `a^(2),b^(2),c^(2)` are in harmonic progression

Answer» Correct Answer - A::B::C
Here, `b=(2ac)/(a+c)" " ……(1)`
and `b^(2)= -2ac" " ….(2)`
`implies b=(-b^(2))/(a+c) implies a+b+c=0`
Now, verify it`
17.

Let` z= a+ ib` (where` a,b,in R` and` i = sqrt(-1)` such that `|2z+3i| = |z^(2)` identify the correct statement(s)?A. `|z|_("maximum")` is equal to `3`B. `|z|_("maximum")` is equal to `1`C. If `|z|_("maximum")` when `z=alpha + ibeta (alpha,beta in R and I = sqrt (-1) then (alpha^(3)+beta^(3))` is equal to `27`D. If `|z|_("maximum") "when" z= + iy (x,y in R "and" i = sqrt(-1) "then" (x^(2) +2y^(2))` is equal to 2`

Answer» Correct Answer - A::B::C::D
Given `|2z+3i| = |z^(2)|`
` because |2z+3i|le2|z|+3`
`implies |z|^(2)le2|z|+3`
`implies 0 le|z|le 3 " "...(1)`
Again `|2z+3i|ge|2|z|-3|`
`implies |z|^(2)ge|2|z|-3|`
`therefore |z|ge1" " …..(2)`
So,(1)`nn`(2)gives
`1le|z|le3`
Also,`|z|_("maximum")impliesz=3i`
So, `alpha=0,beta=3`
`&|z|("maximum") impliesz=-i`
So,`x=0, y=-1`
18.

Let `S` be the set of `2xx2` matrices given by `S={A=[[a,b],[c,d]],"where" a,b,c,d,in I}`, such that `A^(T)=A^(-1)` ThenA. number of matrices in set s is equal to 6B. number of matrices in set S such that `|A-I_(2)| ne 0` is equal to 3C. symmetric matrices are more than skew -symmetric matrices in set SD. all matrices in set S are singular

Answer» Correct Answer - B::C
As, `A A^(T)=I_(2)`
`implies [[a,b],[c,d]],[[a,c],[b,d]]=[[1,0],[0,1]]`
`impliesa=0,b=pm1,d=0,c=pm1`
therefore Total 8 matrices are possible They are
`[[1,0],[0,1]],[[1,0],[0,-1]],[[-1,0],[0,1]],[[-1,0],[0,-1]]`
`[[0,1],[1,0]],[[0,-1],[1,0]],[[0,1],[-1,0]],[[0,-1],[-1,0]]`
Also `|A-I_(2)|=|A-A A^(T)|=|A||I_(2)-A^(T)|`
`=|A||(I_(2)-A^(T))^(T)|=|A||I_(2)-A|`
`=|A||A-I_(2)|`
`implies|A|=1(As,|A-I_(2)|ne 0)`
except `A=1=[[1,0],[0,1]]`
where `|A|=1 but`
`| A-I_(2)|=0`
19.

If M and N are orthogonal matrices of order 3, then which of the following is (are) orthogonal matrix?A. `M^(2017)`B. `M^(T)N`C. `M^(2)N^(2)`D. `MN`

Answer» Correct Answer - A::B::C::D
Given, `MM^(T)=I=M^(T)M`
`&" " N N^(T)=I=N^(T)N`
(A)Let `C=M^(2017)`
Now,`C C^(T)=MM…..MM^(T)M^(T)M^(T)…..M^(T)=1`
(B) Let `D =M^(T)N`
Now, `D D^(T)=M^(T)N(M^(T)N)^(T)`
`= M^(T)N N^(T)M = 1`
(C ) Let `P= M^(2)N^(2)=MMN N`
So, `P P^(T) = MMN N N^(T)N^(T)M^(T)M^(T)`
(D)Let `Q = MN implies Q Q^(T)=M N N^(T)M^(T)=I`
20.

Let `A = [a_(ij)]` be `3 xx 3` matrix given by `a_(ij) = {(((i+j)/(2))+(|i-j|)/(2),if i nej,),((i^(j)-(i.j))/(i^(2)+j^(2)),if i =j,):}` where `a_(ij)` denotes element of `i^(th)` row and `j^(th)` column of matrix `A`. On the basis of above information answer the following question: If `A^(2)+ pA + qI_(3) = 32 A^(-1)`, then `(p +q)` is equal to-A. `-22`B. `-20`C. 21D. `-23`

Answer» Correct Answer - D
We have `A= [(0,2,3),(2,0,3),(3,3,1)]`
`implies |A|= 32 implies A^(-1)` will exist
Also matrix A is non-singular
`therefore` The characteristic equation of matrix A, is
`implies A^(3) - A^(2) - 22A = 32I`
` implies 32A ^(-1) = A^(2) - A - 22I`
`therefore p=-1, q = -22` (on comparing)
`implies(p+q) = - 23`
Also, `A^(2) - A = B^(2) - B^(2)` (Given)
`implies |A||A-I|=|B|^(2)|A-I|`
As `|A-I|ne 0`
`implies |B|^(2) = |A|=32`
`therefore |sqrt(2)BA^(-1)| = (2sqrt(2)|B|)/(|A|)`
`(2sqrt(2)(pm4sqrt(2)))/(32)=(pm16)/(32)=pm(1)/(2)`
21.

Find the remainder when 22013 is divided by 17.

Answer»

We know 24 = 16

The reminder when 24 is divided by 17 is – 122013 = (24)503. 21

∴ The remainder when 22013 is

divided by 17 is (–1)503. 2

= (–1)2 = – 2.

22.

Let `A = [a_(ij)]` be `3 xx 3` matrix given by `a_(ij) = {(((i+j)/(2))+(|i-j|)/(2),if i nej,),((i^(j)-(i.j))/(i^(2)+j^(2)),if i n=j,):}` where `a_(ij)` denotes element of `i^(th)` row and `j^(th)` column of matrix A. On the basis of above information answer the following question: If a `3 xx3` matrix B is such that `A^(2) +B^(2) = A +B^(2)A`, then det. `(sqrt(2)BA^(-1))` is equal toA. `1`B. `(1)/(4)`C. `(1)/(2)`D. `16`

Answer» Correct Answer - C
We have `A= [(0,2,3),(2,0,3),(3,3,1)]`
`implies |A|= 32 implies A^(-1)` will exist
Also matrix A is non-singular
`therefore` The characteristic equation of matrix A, is
`implies A^(3) - A^(2) - 22A = 32I`
` implies 32A ^(-1) = A^(2) - A - 22I`
`therefore p=-1, q = -22` (on comparing)
`implies(p+q) = - 23`
Also, `A^(2) - A = B^(2) - B^(2)` (Given)
`implies |A||A-I|=|B|^(2)|A-I|`
As `|A-I|ne 0`
`implies |B|^(2) = |A|=32`
`therefore |sqrt(2)BA^(-1)| = (2sqrt(2)|B|)/(|A|)`
`(2sqrt(2)(pm4sqrt(2)))/(32)=(pm16)/(32)=pm(1)/(2)`
23.

Consider biquadratic equation `81x^(4) + 216x^(3) + 96x = 65`, whose roots are `a,b,c,d`. Given `a,b`, real roots and `c,d` are imaginary roots. On the basis of above information, answer the followin questions: The Value of `c^(3) + d^(3) - (a+b))^(3)` is equal toA. `(52)/(9)`B. `(53)/(9)`C. `(59)/(9)`D. `(50)/(9)`

Answer» Correct Answer - A
The given equation is ltbgt `(3x+2)^(4) = 81`
`implies ((3x+2)^(2)-9)((3x+2)^(2)+9)=0`
Let `a=(1)/(3),b=(-5)/(3),C=(-2)/(3)+i,d=(-2)/(3)-i`
Now,verfiy it
24.

In how many ways can the letters of the word CHEESE be arranged so that no two E's come together?

Answer»

The given word contains 6 letters in which one C, one H, 3E's and one S.

Since no two E's come together, first arrange the remaining 3 letters in 3! ways. Then we can find 4 gaps between them. The 3E's can be arranged in these 4 gaps in 4P3/3! = 4 ways.

∴ The number of required arrangements = 3! × 4 = 24

25.

Consider biquadratic equation `81x^(4) + 216x^(3) + 216x^(2) +96x = 65`, whose roots are `a,b,c,d`. Given `a,b`, real roots and c,d are imaginary roots. On the basis of above information, answer the followin questions: The value of `(a+b)^(3) - (c+d)^(3)` is equal to-A. `(-128)/(3)`B. 0C. `(-64)/(3)`D. `(-142)/(9)`

Answer» Correct Answer - B
The given equation is ltbgt `(3x+2)^(4) = 81`
`implies ((3x+2)^(2)-9)((3x+2)^(2)+9)=0`
Let `a=(1)/(3),b=(-5)/(3),C=(-2)/(3)+i,d=(-2)/(3)-i`
Now,verfiy it
26.

Find the number of ways of selecting 4 English, 3 Telugu and 2 Hindi books out of 7 English, 6 Telugu and 5 Hindi books.

Answer»

The number of ways of selecting

4 English books out of 7 books = 7C4

3 Telugu books out of 6 books = 6C3

2 Hindi books out of 5 books = 5C2

Hence, the number of required ways

7C4 × 6C3 × 5C2 = 35 × 20 × 10 = 7000.

27.

Form the polynomial equation whose roots are cubes of the roots of x3 + 3x2 + 2 = 0

Answer»

Given equation is x3 + 3x2 + 2 = 0

Put y = x3 so that x = y1/3

∴ y + 3y2/3 + 2 = 0

3y2/3 = – (y + 2)

Cubing on both sides, 27y2 = – (y + 2)3

= – (y3 + 6y2 + 12y + 8)

∴ y3 + 6y2 + 12y + 8 = 0

⇒ y3 + 33y2 + 12y + 8 = 0

Required equation is x3 + 33x2 +12x +8= 0

28.

If x = a/(b-c), y = b/(c-a), z = c/(a-b) then what is the value of the following?(a).  0(b).  1(c).  abc(d).  ab + bc + ca

Answer»

We have x = \(\frac{a}{b-c},\) y = \(\frac{b}{c-a},\) z = \(\frac{c}{z-b}\)

Now, \(\begin{vmatrix}1&-x&x\\1&1&-y\\1&z&1\end{vmatrix}\) = \(\begin{vmatrix}1&-x&x\\0&1+x&-(x+y)\\0&x+z&1-x\end{vmatrix}\) (By applying R2 - 1 R2 - R1 and R3 - 1, R3 - R2)

 = (1 + x) (1 - x) + (x + y)(x + z) (By expanding determinant along C1)

 = 1 - x2 + x2 + xy + xz + yz

 = 1 + \(\frac{a}{b-c}\times\frac{b}{c-a}\) + \(\frac{a}{b-c}\times\frac{c}{a-b}\) + \(\frac{b}{c-a}\times\frac{c}{a-b}\) 

 = 1 + \(\frac{ab(a-b)+ac(c-a)+bc(b-c)}{(a-b)(b-c)(c-a)}\) 

 = 1 + \(\frac{a^2b-ab^2+ac^2-a^2c+b^2c-b^2c}{(a-b)(b-c)(c-a)}\) 

 = \(\frac{(a-b)(b-c)(c-a)+a^2b-ab^2+ac^2-a^2c+b^2c-bc^2}{(a-b)(b-c)(c-a)}\) 

 = \(\frac{(-a^2b-ac^2+a^2c-b^2c+ab^2+bc^2)+(a^2b-ab^2+ac^2-a^2c+b^2c-bc^2)}{(a-b)(b-c)(c-a)}\) 

 = \(\frac{0}{(a-c)(b-c)(c-a)}\)

 = 0

29.

\( \left|\begin{array}{ccc}a+b+c & -c & -b \\ -c & a+b+c & -a \\ -b & -a & a+b+c\end{array}\right|=2(a+b)(b+c)(c+a) \)

Answer»

\(\begin{vmatrix}a+b+c&-c&-b\\-c&a+b+c&-a\\-b&-a&a+b+c\end{vmatrix}\)

Applying C1→ C1 + C2 & C2 → C2 + C3

\(=\begin{vmatrix}a+b&-(b+c)&-b\\a+b&b+c&-a\\-(a+b)&b+c&a+b+c\end{vmatrix}\)

Applying C→ \(\frac{C_1}{a+b}\) & C2 → \(\frac{C_2}{b+c}\)

= (a + b)(b + c)\(\begin{vmatrix}1&-1&-b\\1&1&-a\\-1&1&a+b+c\end{vmatrix}\)

Applying R→ R2  - R1, & R→ R3 + R1

 = (a + b)(b + c)\(\begin{vmatrix}1&-1&-b\\0&2&-a+b\\0&0&a+c\end{vmatrix}\)

= 2(a + b) (b + c) (c + a) (Expand determinant along C1)

30.

\( \left|\begin{array}{ccc}x & y & z \\ x^{2} & y^{2} & z^{2} \\ x^{3} & y^{3} & z^{3}\end{array}\right|=x y z(x-y)(y-z)(z-x) \)

Answer»

 \(\begin{vmatrix}x&y&z\\x^2&y^2&z^2\\x^3&y^3&z^3\end{vmatrix}\)

Applying C1 → \(\frac{C_1}x\), C2 → \(\frac{C_2}y\) & C3 → \(\frac{C_3}z\)

\(=xyz\begin{vmatrix}1&1&1\\x&y&z\\x^2&y^2&z^2\end{vmatrix}\)

Applying C1 → C1 - C2  and C2 → C2 - C3

\(=xyz\begin{vmatrix}0&0&1\\x-y&y-z&z\\x^2-y^2&y^2-z^2&z^2\end{vmatrix}\)

\(=xyz\begin{vmatrix}0&0&1\\x-y&y-z&z\\(x-y)(x+y)&(y+z)(y-z)&z^2\end{vmatrix}\)

Applying C1 → \(\frac{C_1}{x-y}\) and C2 → \(\frac{C_2}{y-z}\)

= xyz(x - y)(y - z)\(\begin{vmatrix}0&0&1\\1&1&z\\x+y&y+z&z^2\end{vmatrix}\)

= xyz(x - y)(y - z)\(\begin{vmatrix}1&1\\x+y&y+z\end{vmatrix}\) (By Expanding determinant along R1)

= xyz(x - y) (y - z) (y + z - (x + y))

= xyz(x - y) (y - z) (z - x)

31.

Find the number of 15th roots of unity, which are also 25th roots of unity.

Answer»

The number of common roots = H.C.F of {15, 25} = 5

32.

If z = 2 − i√7 , then show that 3z3 – 4z2 + z + 88 = 0.

Answer»

Given z = 2− i√7

⇒ z – 2 = − i√7

⇒ (z – 2)2 = (− i√7)2

⇒ z2 – 4z + 4 = 7i2

⇒ z2 – 4z + 4 = – 7

⇒ z2 – 4z + 11 = 0

3z3 –4z2 + z + 88 = 3z(z2 – 4z + 11) + 8z2 – 32z + 88

= 3z(0) + 8(z2 – 4z + 11) = 0 + 8(0) = 0

∴ 3z3 – 4z2 + z + 88 = 0

33.

Solve: \( \frac{a x}{b}-\frac{b y}{a}=a+b, a x-b y=2 a b \).

Answer»

\(\frac{ax}{b} - \frac{by}{a} = a + b\)   ....(1)

\(ax - by = 2ab\)      ....(2)

From (2), we get

\(\frac{ax - by}{a} = 2b\)

⇒ \(x - \frac ba y = 2b\)     .....(3)

Subtract equation (3) from (1), we obtain

\(\left(\frac ab -1\right)x = a - b\)

⇒ \(\left(\frac {a-b}b\right)x = a - b\)

⇒ x = b

∴ From (3), we get 

\(b - \frac ba y = 2b\)

⇒ \( \frac ba y = b-2b\)

⇒ \( \frac ba y = -b\)

⇒ y = -a

Hence, x = b, y = -a be solution of given system of equations.

34.

What should be added in 3 and 5, so that the ratio becomes 2 : 3?1. 22. 33. 14. 45. 6

Answer» Correct Answer - Option 3 : 1

Given:

Numbers are 3 and 5

Final ratio = 2 : 3

Calculation:

Let x is added in both the terms.

(3 + x)/(5 + x) = 2/3

⇒ 3(3 + x) = 2(5 + x)

⇒ 9 + 3x = 10 + 2x

⇒ x = 1

The number to be added is 1

35.

A rational number has its denominator greater than its numerator by 6. If the numerator is increased by 4 and the denominator is decreased by 8, the number becomes 5/3. What is the original rational number ?1. 11/172. 5/173. 7/134. 13/19

Answer» Correct Answer - Option 1 : 11/17

Concept used:

The numerator is the upper part and denominator is the lower part of any fraction

Calculation:

Let the numerator of the rational number be x then its denominator be x + 6

Rational number = Numerator/Denominator

The original rational number = x/(x + 6)

Now, A/Q

(x + 4)/(x + 6 – 8) = 5/3

⇒ (x + 4)/(x – 2) = 5/3

⇒ 3(x + 4) = 5(x – 2)

⇒ 3x + 12 = 5x – 10

⇒ 2x = 22

⇒ x = 11

Numerator = x and Denominator = 11 + 6 = 17

∴ The original rational number is 11/17

36.

निम्नलिखित शब्दों को शब्दकोश में दिए गए क्रम के अनुसार लिखिए : 1. Defect 2. Defence 3. Deerstalker 4. DefensiveA. 2, 3, 1, 4B. 1, 3, 2, 4C. 4, 3, 1, 2D. 3, 1, 2, 4

Answer» Correct Answer - D
शब्दकोश के अनुसार शब्दों का क्रम :
`{:("3. Deerstalker"),(" " darr),("1. Defect"),(" " darr),("2. Defence"),(" "darr),("4. Defensive"):}`
37.

The green density for a stainless steel powder compact is targeted at 6.5 g/cm3 . The apparent density for the powder is 2.7 g/cm3 . What is the compression ratio and what is the required powder fill for a final height of 40 mm?

Answer»

P1 = 6.5 g/cm3

P2 = 2.7 g/cm3

H2 = 40 mm

H1= ?

We know that

P1H1 = P2H2

6.5 x H1 = 2.7 x 40

H1 = 108/6.5

H1 = 16.61 mm

38.

Bohar atomic theory postulates.

Answer»
The postulates of Bohr's model of an atom are
1. Electrons revolve around the nucleus of an atom in a certain definite path called the Orbit or stationary state of the shell.
2. The shells are having different energy levels denoted as K, L, M, N.
3. As long as the electron remains in an orbit, it neither absorbs nor emits energy.
4. The electron can move only in that orbit in which angular momentum is quantized, i.e., the angular momentum of the electron is an integral multiple of h/



39.

.What B O D? What is its significance?

Answer»

It determines the rate of respiration in living beings. Measuring BOD gives the COD or Chemical Oxygen Demand of inorganic substances. It indicates the polluting potential of water. BOD is used in the medical and pharmaceutical industries to measure the oxygen consumption of cell cultures.

40.

कौन-सा शब्द अंग्रेजी शब्दकोश में पहले आता है ?A. CarromB. CrammingC. CarrierD. Cartoon

Answer» Correct Answer - C
शब्दकोश के अनुसार शब्दों का क्रम :
`{:("3. Carrier"),(" " darr),("1. Carrom"),(" " darr),("4. Cartoon"),(" "darr),("2. Cramming"):}`
41.

निम्नलिखित शब्दों को शब्दकोश में दिए गए क्रम के अनुसार लिखिए : 1. Incompatible 2. Incomparable 3. Incongruous 4. InconsistentA. 2, 1, 4, 3B. 3, 4, 2, 1C. 4, 2, 1, 3D. 2, 1, 3, 4

Answer» Correct Answer - D
शब्दकोश के अनुसार शब्दों का क्रम :
`{:("2. Incomparable"),(" " darr),("1. Incompatible"),(" " darr),("3. Incongruous"),(" "darr),("4. Inconsistent"):}`
42.

Name the enzyme involved photosynthesis?

Answer»

Major enzymes involved in photosynthesis:

ATP synthase- synthesis of ATP

RUB is CO-captures carbon dioxide from the atmosphere

PEP carboxylase- fix carbon dioxide in the cells of the mesophyll

Carbonic anhydrase- releases CO from the dissolved hydrocarbonate ions

Oxygenase - catalyses the oxygenation reactions.

43.

निम्नलिखित शब्दों को शब्दकोश में दिए गए क्रम के अनुसार लिखिए : 1. Diffident 2. Difficult 3. Different 4. DiffidenceA. 1, 2, 3, 4B. 3, 2, 4, 1C. 2, 1, 3, 4D. 3, 2, 1, 4

Answer» Correct Answer - B
शब्दकोश के अनुसार शब्दों का क्रम :
`{:("3. Different"),(" " darr),("2. Difficult"),(" " darr),("4. Diffidence"),(" "darr),("1. Diffident"):}`
44.

In modern sense, which of the following refers to a set of actual and potential buyers of a product or service?A. MarketingB. MarketC. SalesD. Place

Answer» Correct Answer - (b) Market
45.

Write any five characteristics of phyllum annelid

Answer»
The characteristics of annelid are ---
The Annelids are coelomate and triploblastic.
•They exhibit organ system level organization.
•Their body is segmented.
•They respire through their body surface.
•Nephridia are the excretory organs.
•They have a well-developed circulatory and digestive system.
46.

Give reason:Dialysis is not complete treatment

Answer»

Dialysis is not complete treatment because dialysis does some of the work of healthy kidneys, but it does not cure your kidney disease. You will need to have dialysis treatments for your whole life unless you are able to get a kidney transplant.

47.

Explain the concept of Management as a Science?

Answer»

Management as a Science- Science means a systematic body of knowledge pertaining to a specific field of study. It contains general principles and facts which explains a phenomenon. These principles establish cause-and-effect relationship between two or more factors. Scientific methods of observations and experiments are used to develop principles of science.

48.

Mention any 2 Taxonomical tools.

Answer»

Herbarium and Botanical garden may be used as tools for the plant taxonomy. Museum, Taxonomical keys and Zoological parks are classical tools for animal studies. Field visits, survey, identification, classification, preservation and documentation are the important components of taxonomical tools.

49.

Last year I _____ to America. A) was go B) go C) was going D) went

Answer»

Correct option is D) went

50.

Significance of taxonomical classification

Answer»

Taxonomy is the science of classifying organism. Taxonomy is the basis for all meaningful studies on biodiversity, pest management, medicine, bioprospecting, fisheries, quarantine, defense etc. Taxonomy provides basic understanding about the components of biodiversity which is necessary for effective decision-making about conservation and sustainable use.In short, taxonomy provides the basic foundations of conservation practice and sustainable management of the world remaining resources.