Explore topic-wise InterviewSolutions in Current Affairs.

(a) Carbon tetrachloride (CCl₄)

(b) Carbon dioxide (CO₂)

Correct option is (C) (A), (C) only

Bond strength \(\propto\) Bond order

removal of electron from antibonding MO increases B.O. 

NO & O₂, has valence e in π*orbital.

(A) The refractive indices of the dispersed phase and the dispersion medium differ greatly in magnitude.

The diameter of dispersed particle should be somewhat below or near the wavelength of light.

Viscosity of liquids decrease as temperature rises.

Correct option is (c) p⁺³

The F ions make the enamel on teeth much harder by converting hydroxyapatite, [3(Ca₃(PO₄)₂ Ca(OH)₂], the enamel on the surface of the teeth, into much harder fluorapatite, [3(Ca₃(PO₄)₂.CaF₂].

Isoelectronic pair : Na⁺, F^-

Correct option is (c) Be

Be and Mg are the s-block elements that do not give flame test

Correct option is (a) Cesium

Cesium gives blue flame test.

THE STRUCTURE IS OF CIMETIDINE.

Correct option is (C) Cimetidine

Correct answer is 2

Statement II and III are false

Statement I and IV are correct match 

Positive solution: FeCl₃ + hot water

Negative solution: FeCl₃ + hot NaOH

Correct answer is 3

I) II) and III) are correct Statement IV) is false, Cu (II) is used as a reactant in Fehling's solution.

(1)

CuO + H₂ → Cu + H₂O

Given : Ideal gas A and H2 gas at same pressure and volume. 

From ideal gas equation pv = nRT 

n₁T₁ = n₂T₂ 

\(\frac{3}{GMM \,of\,A}\times300\) = 0.2/2 x 200 

GMM of A = 45 g/mole

Correct option is (3) \((\frac{dE}{dT})_p=0.1 \times 10^{-4}\) 

Metal which have lower value of \((\frac{dE}{dT})_p\) is best used for standard half electrode.

For mixture.

PV = nRT

1 x 2 = n_Total x 1/12 x 300

n_Total = 24/300 = 0.08 Mole

\(n_{H_{2}}\)+ \(n_{O_{2}}\) = 0.08

(i) \(W_{H_{2}}\) + \(W_{O_{2}}\)= 0.76

(ii) \(W_{H_{2}}\)/2 + \(W_{O_{2}}\)/32 = 0.08

16\(W_{H_{2}}\) + \(W_{O_{2}}\)= 0.08 x 32;

\(W_{H_{2}}\) = (0.08 x 32 - 0.76 / 15) = 0.12 ; 

\(W_{O_{2}}\) = 0.64

So \(n_{H_{2}}\) = 0.12/2 = 0.06 ;

\(n_{o_{2}}\) = 0.64 / 32 = 0.02

= 3

Since carbon atoms can achieve the inert gas electron arrangements only by the sharings of electrons, therefore, carbon always forms covalent bonds.

(d) C₆H₅NH₂ and ClCH₂ – CHO

Correct answer is  (b) Quinone

(c) Pyridine

(d) Electronic configuration of He is 1s²

Given:

A shopkeeper sells a dozen pair of socks whose marked price is Rs. 600 at 20% discount. 

Concept used:

Profit and loss

Calculation:

20% discount is offered on Rs.600

SP = 600 - (20% of 600)

SP = 600 - 120

SP = Rs.480

Selling price of one pair of socks = 480/12

SP = 40

AS per the question,

⇒ 320/40 = 8

8 pair of socks can be bought for Rs.320

Given:

A dozen pairs of gloves worth Rs.600 are available at a discount of 10%.

Formula used:

Selling price = Marked price (100 – D%)/100

Calculation:

Marked price of 12 pair of gloves = Rs. 600

Selling price of 12 pairs of gloves after discount

⇒ 600(100 – 10)/100

⇒ Rs. 540

If cost price of of 12 pair is Rs. 540 = (12 × 270)/540

⇒ 6 pairs

∴ 6 pair of gloves can be bought for Rs. 270.

Given:

8 - digit number = 7y9745x2

Divisor = 72

Concept used:

First, we should have to know the factors of divisor if all the factors are divided the given number, then the number is divisibly by 72

Divisibility rule of 8: If the last three digits are divisible by then the number is divisible by 8

Divisibility of 9:  If the sum of all digits is divisible by 9 then the number is divisible by 9

2 and 4 are the factors of 8 so, if the number is divisible by 8 is also divisible by 2 and 4

3 is the factor of 9 so, if the number is divisible by 9 then the number is divisible by 3

2 and 3 are the factors of 6 

Calculations:

Factors of 72 = 1 , 2, 3, 4, 6, 8, 9

To verify the number is divisible by 8 last three digits = 5x2

If the 6x6 is divisible by 8  then the number must be 512 or 552 or 592

Hence, x = 1 or 5 or 9

To verify the number is divisible by 9 sum of digits =7 + y + 9 + 7 + 4 + 5 + x + 2

⇒ 34 + y + x

34 + y + x is divisible by 9 it must be 36 or 45 

34 + y + x = 36

⇒ x + y = 36 - 34

⇒ x + y = 2

If we substitute x = 1

1 + y = 2

⇒ y = 2 - 1

⇒ y = 1

Here, the condition is x > y so  x = 1 doesnot satisfy this condition 

Let take the  number must be 45

⇒ x + y = 45 - 34

⇒ x + y = 11

If we substitute x = 1

1 + y = 11

⇒ y = 11 - 1

⇒ y = 10

x > y  but the codition doesnt satisfy 10 is a 2 - digit number 

If we substitute x = 5

5 + y = 11

⇒ y = 11 - 5

⇒ y = 6

x < y for this condition so it doesnt satisfy

If we substitute x = 5

9 + y = 11

⇒ y = 11 - 9

⇒ y = 2

x > y so the condition satisfieed 

2x - y = 2 × 9 - 2

⇒ 18 - 2 = 16

∴ The required value is 16

Given:

Let the number of floors are 2x and x

(2x + x)/2 = 15

X = 10

number of floors in tower A = 20

Number of floors in tower B = 10

Number of houses on each floor of tower A = (1/2) of 20

= 10

Total number of houses in tower A = 10 × 20

= 200

Number of houses on each floor of tower B = (1/2) of 20

= 10

Total number of houses in tower B = 10 × 10

= 100

Total number of houses in both the towers = 200 + 100

= 300

Given:

The given number = 13824

Concept:

Calculation skills trick

Calculation:

Step(1):

First, we will take the digit at the unit’s place.

At the unit place, we have 4.

Step(2):

Now consider the cube table, the cube of which number has 4 as at the unit digit place.

We see, 4 × 4 × 4 = 64.

Step(3):

That means the cube root of 13824 will have 4 at the unit place.

Step(4):

Now ignore the last 3 digits of 13824, i.e. 824

Step(5):

Taking 59 as a reference number, we can see from the cubes table 13 lies between cubes of 2 and 3.

Step(6): Here, we choose the lower number i.e. 2

∴ We get the two digit of the answer

∴ Cube root of 13824 = 24

Concept:

Suppose a set of n objects has n1 of one kind of object, n2 of a second kind, n3 of a third kind, and so on with n = n1 + n2 + n3  +...+ nk then the number of distinguishable permutations of the n objects is  = \(\frac{{{\rm{n}}!}}{{{{\rm{n}}_1}! \times {{\rm{n}}_2}! \times {{\rm{n}}_3}! \ldots \ldots \ldots {{\rm{n}}_{\rm{k}}}!}}\)

Calculation:

Given: Three a’s and two b’s

Total number = 3 + 2 = 5

In the set of 5 words has 3 words of one kind and 2 words of the second kind.

Therefore, Number of different messages that can be represented by three a's and two b's = \(\frac{{5!}}{{3!2!}} = 10\)

Given:

Total number of floors = 90

Calculation:

Let the total number of floors in building Y be a.

Number of floors in building X = a - 10

⇒ a - 10 + a = 90

⇒ 2a = 100

⇒ a = 50

number of floors in building X is 40

number of floors in building Y is 50

Required ratio = 40 : 50

4 : 5

Given:

Sonia income = 4  × (Ranjeet’s income)

Ram expenditure = 200 % of Ranjeet’s income

Ram’s income = Rs.80,000

Ram’s saving = 20,000 + Sonia’s income

Calculation:

Let the Ranjeet’s income is Rs. x

Ram’s expenditure = 200% of x

= 2x

sonia’s income = 4x

Ram’s saving = Sonia's income + 20,000

= 4x + 20,000

Ram’s income = expenditure + saving

⇒ 80,000 = 2x + 4x + 20,000

⇒ x = 10,000

Sonia's income = Rs. 40,000

Ratio of income = 40,000 : 10,000 : 80,000

= 4 : 1 : 8

GIVEN:

⇒ Total members = 7 members

⇒ Men = 5

⇒ Women = 4

CALCULATION:

Possible cases:

1) 5 men and 2 women.

2) 3 men and 4 women.

⇒ ⁵C₅ x ⁴C₂ + ⁵C₃ x ⁴C₄

Given:

Profit = 120% of the cost

Cost increases by 25%

Concept used:

Profit = [(SP – CP)/CP] × 100

SP = selling price

CP = cost price

Calculation:

Let CP be Rs. 5x

Profit = 5x × 6/5

⇒ 6x

SP = 5x + 6x

⇒ 11x

New CP = 5x × 5/4

⇒ 25x/4

New profit = (11x – 25x/4)

⇒ 19x/4

Required % = (19x/4 ÷ 11x) × 100

⇒ 19/44 × 100

⇒ 43.18 ≈ 43%

∴ Required % is 43%

GIVEN:

Total amount = Rs. 31,500

⇒ A : B = 6x : 5x

⇒ B : C = 5x : 10x

⇒ A : B : C = 6x : 5x : 10x

CALCULATION:

⇒ A : B : C = 6x : 5x : 10x

⇒ Total amount = 21x

⇒ 21x = Rs. 31,500

⇒ 1x = Rs. 1500

⇒ Amount received by A + B = 11 x 1500

⇒ Amount received by A + B = 16,500

Solution:

Given:

Number = 93

Calculation:

Let the first part is x and second part is y

⇒ 3x/2y = 25/4

⇒ x/y = 25/6

⇒ x = 25/31 × (93)

⇒ 75

∴ The required result will be 75.

(b) Both, A and R, are true and R is the correct explanation of A 

(b) Both, A and R, are true and R is the correct explanation of A 

(b) Both, A and R, are true but R is not the correct explanation of A

(a) Both, A and R, are true and R is the correct explanation of A 

Correct option is C) that the passengers became frightened

Correct option is A) such a busy man