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 number of waves make by a Bohr electron in an orbit of maximum magnetic quantum number +2 is .

Answer»


Solution :For `m_l = + 2` (maximum),l=2 and n=3
NUMBER of WAVES in a SHELL = n=3 .
Discussion
2.

The number of waves in an orbit are

Answer»

`N^(2)`
n
`n-1`
`n-2`

SOLUTION :The number of waves in an orbit is equal to n. (PRINCIPAL QUANTUM number)
Discussion
3.

The number of water molecules required to hydrolyse 1 mole of borax is :

Answer»


ANSWER :5
Discussion
4.

The number of water molecules present in a drop of water (volume 0.0018 ml) density = 1 gmL^-1 at room temperature is

Answer»

`1.084xx10^(18)`
`6.023xx10^(19)`
`4.84 xx10^(17)`
`6.023 xx10^(23)`

Answer :B
Discussion
5.

The number of water molecules present in a drop of water (volume = 0.0018mL) at room temperature is

Answer»

`1.084 xx 10^(18)
`6.023 xx 10^(23)`
`3.01 xx 10^(23)`
`6.023 xx 10^(23)`

SOLUTION :B) Number of moles = (Weight)/(Molecular weight)
`=(0.0018)/(18) = 1 xx 10^(-4)`
[`therfore` 0.0018 mL = 0.0018g]
Number of water MOLECULES `=1 xx 10^(-4) xx 6.023 x 10^(23)`
`=6.023 xx 10i^(19)`
Discussion
6.

The number of water molecules is maximum in :

Answer»

18 GRAM of WATER
18 MOLES of water
18 molecules of water
1.8 gram of water

Solution :`because` 1 mole water `= 6.02xx1^(23)` molecules
`THEREFORE` 18 mole water `= 18xx6.02xx10^(23)` molecules so, 18 mole water has maximum number of molecules.
Discussion
7.

The number of water molecules in one litre of water is:

Answer»

18
`18 xx 1000`
`6.022 xx 10^(23)`
`3.3 xx 10^(25)`

Solution :One litre WATER (1000 G) contains 55.55 moles.
Discussion
8.

The number of water molecules in a drop of water weighing 5 mg is

Answer»

`6.023 XX 10^(72)`
`3.0125 xx 10^(21)`
`1.67 xx 10^(20)`
`1.67 xx 10^(21)`

ANSWER :C
Discussion
9.

The number of water molecules in a drop of water weighing 0.018 g is

Answer»

`6.022xx10^(26)`
`6.022xx10^(23)`
`6.022xx10^(20)`
`9.9xx10^(22)`

SOLUTION :WEIGHT of the water drop=0.018g
No. of moles of water in the drop=Mass of water/molar mass
=0.018/18=`10^(-3)` mole
No of water molecules present in 1 mole of water =`6.022xx10^(23)`
No. water molecules in one drop of water (`10^(-3)` mole)=`6.022xx10^(23)xx10^(-3)`
`=6.022xx10^(20)`
Discussion
10.

The number of water molecules are associated with washing soda is X, then X-l=

Answer»


SOLUTION :Washing sodaformulais `Na_(2)CO_(3).10H_(2)O`
therefore X=10` and X-1 =9
Discussion
11.

The number of water molecule (s) directly bonded to the metal centre in CuSO_(4) .5 H_(2) O is

Answer»


SOLUTION :`(4H_(2) O`
molecular are directily BONDED to Cu )
Discussion
12.

The number of unpaired electrons in carbon atom in excited state is

Answer»

One
Two
Three
Four

Solution :`C_6 = 1s^2 , 2s^2 2p^2` (GROUND STATE)
`=1s^2 ,2s^1 , 2p_x^1 2p_y^1 2p_z^1` (Excited state)
In excited state no. of UNPAIRED ELECTRON is 4
Discussion
13.

The number of unit cells present in 1 mole of NaCl crystal is

Answer»

`6.023 GT O^(-2) gt N^(-3)`
`N^(-3) gt O^(-2) gt F^(-)`
`O^(-2) gt N^(-3) gt F^(-)`
`F^(-)N^(3) gt O^(-2)`

Answer :B
Discussion
14.

The number of types of bonds between two carbon atoms in calcium carbide is

Answer»

ONE SIGMA , TWO pi
one sigma, one pi
two sigma , one pi
two sigma, two pi

Answer :A
Discussion
15.

The number of three centred, two electron bonds in diborane is

Answer»

2
4
3
6

Answer :A
Discussion
16.

The number of tetrahedral voids per unit cell in NaCl crystal is ____

Answer»

4
8
twice the number of octahedral voids
FOUR times the number of octahedral voids .

Solution :NaCl has FCC arrangement of `Cl^-` IONS. HENCE, number of `Cl^-` ions in packing per UNIT cell =4. No. of tetrahedral voids is double the number of octahedral voids. Hence, tetrahedral voids =8
Discussion
17.

The number of tetrahedral voids per unit cell in NaCl crystal is ……..

Answer»

4
8
Twice the number of octahedral voids.
Four TIMES the number of octahedral voids.

Solution :NaCl has FCC arrangement of ` CL^(-)`ions. Hence, number of `Cl^(-)`ions in packing per UNIT cell = 4.
NO. of tetrahdral voids is DOUBLE the number of octahedral voids. Hence, tetrahedral voids = 4.
Discussion
18.

The number of tetrahedral voids in the unit cell of a face- centred lattice of similar atoms is

Answer»

4
6
8
12

Solution :A face- centred cubic lattice has 4 ATOM per UNIT CELL in the packing . No. of tetrahedral voids is DOUBLE the number of atoms in the packing .
Discussion
19.

The number of tetrahedral voids in the unit cell of a face centred cubic lattice of similar atoms is

Answer»

4
6
8
10

Solution :NUMBER of tetrahedral voids in f.c.c. unit cell of SIMILAR ATOMS =8
Discussion
20.

The number of tetrahedral voids in the unit cell of a face-centred cubic lattice of similar atoms is

Answer»

4
6
8
10

Solution :In F.C.C. STRUCTURE TETRAHEDRAL VOID = No. of CORNER = 8
Discussion
21.

The number of tertiary carbons and quaternary hydrogens in neopentane respectively are

Answer»

1 and 1
1 and 0
1 and 2
0 and 0

Answer :D
Discussion
22.

The number of teritary carbon atoms in tertiary butyl alcohol is

Answer»

3
2
1
4

Answer :C
Discussion
23.

The number of pi electrons in benzene is

Answer»

3 
6 
9 
12 

Answer :B
Discussion
24.

The number of sulphur atoms present in 0.2 mole of sodium thiosulphate is (N=Avogadro number)

Answer»

4N
0.2 N
0.4 N
0.1 N

Answer :C
Discussion
25.

The number of subshells is always equal to the order of the orbit.

Answer»


ANSWER :F
Discussion
26.

The number of sub levles in the quantum level n = 3 is

Answer»

1
2
3
4

Solution :`N^(TH)` SHELL CONTAIN n SUBSHELLS
Discussion
27.

The number of structural isomers possible for C_(7)H_(16) is __________

Answer»


SOLUTION :`C-C-C-C-C-C-C`
`C-UNDERSET( C )underset(|)C-C-underset( C )underset(|)C-C""C-underset( C )underset(|)C-C-C-C-C`
`C-C-underset( C )underset(|)OVERSET( C )overset(|)C-C-C""C-C-underset( C )underset(|)C-C-C-C`
`C-C-underset( C )underset(|)underset( C )underset(|)C-C-C""C-underset( C )underset(|)overset( C )overset(|)C-C-C-C`
`C-overset( C )overset(|)C-overset( C )overset(|)underset( C )underset(|)C-C""C-underset( C )underset(|)C-underset( C )underset(|)C-C-C`
Discussion
28.

The number of structural isomers obtained by mono-halogenation of propane is

Answer»

TWO
THREE
four
five

SOLUTION :C - C - C - CL`C- undersetoverset(|)(Cl)( C) - C `
Discussion
29.

The number of structural isomers for C_6H_14 is

Answer»

3
4
5
6

Solution :FIVE
Discussion
30.

The number of structural and configurational isomers of a bromo compound, C_(5)H_(9)Br, formed by the additionn of HBr to 2-penthyne respectively are

Answer»

1 and 2
2 and 4
4 and 2
2 and 1

Solution :ADDITION of HBr to 2-pentyne gives two STRUCTURAL isomers (I) and (II).
`CH_(3)-C-=C-CH_(2)CH_(3) OVERSET(HBr) underset((I))(CH_(3)C(Br)=CHCH_(2)CH_(3))+underset((II))(CH_(3)CH=C(Br)CH_(2)CH_(3))`
Each one of these will EXIST as a PAIR of geometrical isomers as shown below:

thus, there are two structural and four configurational isomers.
Discussion
31.

The number of structural and configurational isomers ofa bromo compound , C_5H_9Br formed by the addition of HBr to 2-pentyne respectively are :

Answer»

1 and 2
2 and 4
4 and 2
2 and 1

Solution :Markovnikov's and anti-Markovnikov's ADDITION of HBr gives TWO structural isomers, i.e., `CH_3C-=C CH_2CH_3 overset"HBr"to CH_3CH=C(Br)CH_2CH_3 + CH_3C(Br)=CHCH_2CH_3`
Each of these two isomers can exist as a PAIR of cis, trans-isomers and HENCE there are four configurational isomers.
Discussion
32.

The number of stereoisomers possible for a compound of the molecular formula CH_3 - CH = CH - CH (OH)- Meis

Answer»

2
4
6
8

Solution :
TOTAL POSSIBLE ISOMERS are four.
CIS - R , TRANS - R , cis - S , trans - S
Discussion
33.

Thenumber of stereoisomers of 1,2-dihydroxycylopentane is ….

Answer»

1
2
3
4

Answer :C
Discussion
34.

The number of vertebrates is ...

Answer»

1
2
3
4

Answer :C
Discussion
35.

The number of stereoisomers obtained by bromination of trans-2-butene is :

Answer»

1
2
3
4

Answer :A
Discussion
36.

The number of stereoisomeric products obtained by the addition of HBr to 2-butene

Answer»

FOUR
THREE
TWO
ONE

SOLUTION :ONE
Discussion
37.

The number of spherical nodes and planar nodes present in 4d_(x^(2) - y^(2)) and ......and ........respectively.

Answer»


ANSWER :1, 2
Discussion
38.

The number of silver atoms present in a 90% pure silver wire weighing 10 g is (Ag = 108)

Answer»

`5.57xx10^(22)`
`0.62xx10^(23)`
`5.0 xx10^(22)`
`6.2 xx10^(29)`

SOLUTION :Amount of PURE silver in 10 g of`90%` sample = 9 g
108 g of Ag CONTAINS `6XX10^(23)` ATOMS of Ag
9 gm of Ag contains `(6xx10^(23)xx9)/(108)`
`=0.5xx10^(23)=5xx10^(22)` atoms of Ag
Discussion
39.

The number of significant figures in it are

Answer»

One
Two
Three
Infinite

Answer :D
Discussion
40.

The number of significant figures in electronic charge 1.602 xx 10^(@)C

Answer»

1
2
3
4

Answer :D
Discussion
41.

The number of significant figures in 3.040 dm is

Answer»

infinite
three
two
four

Solution :ZEROES at the end of a NUMBER (greater than 1) that CONTAINS a DECIMAL POINT are alwayssignificiant.
Discussion
42.

The number of significant figures in each of these given numbers respectively are (i) 506.20 (ii) 0.003402

Answer»

4, 5
4,4
5, 4
5, 6

Solution :`506.20=5,0.003402=4`
Discussion
43.

The number of significant figures in 6.0023 are

Answer»

5
4
3
1

Solution :NUMBER of SIGNIFICANT FIGURES in 6.0023 are 5 because all the zeroes stand between TWO non zero DIGIT counted towards significant figures.
Discussion
44.

The number of significant figures in 10500

Answer»

Three
Four
Five
Can be any of these

Answer :A
Discussion
45.

The number of significant figures in 0.0045 are

Answer»

Two
Three
Four
Five

Answer :A
Discussion
46.

The number of sigma of pi-bonds in butene 3-yne are

Answer»

5 SIGMA and 5 pi
7 sigma and 3 pi
8 sigma and 2 pi
6 sigma and 4 pi.

Answer :B
Discussion
47.

The number of sigma (sigma) bonds in 1-butene is ………

Answer»

8
10
11
12

Solution :`H- underset(underset(H)(|))(C )= underset(underset(H)(|))( C)- underset(underset(H)(|))OVERSET(overset(H)(|))(C )- underset(underset(H)(|))overset(overset(H)(|))(C )-H, 11 SIGMA` BOUNDS and `1pi` BOND
Discussion
48.

The number of sigma (sigma) and pi (pi) bonds in pent-2-en-4-yne is ……

Answer»

`13 sigma`-BONDS and no `PI`-bonds
`10 sigma`-bonds and no `3 pi`-bonds
`8 sigma`-bonds and no `5 pi`-bonds
`11 sigma`-bonds and no `2 pi`-bonds

Solution :`H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)(C)=underset(H)underset(|)(C)-C-=C-H`
`{:(,,sigma,pi),(sigma-"bonds = 10",-,1,0),(pi-"bonds=3",=,1,1),(,-=,1,2):}`
Discussion
49.

The number of sigma and pi bonds present in ethene is

Answer»

`6sigma and no PI`
`3sigma and no pi`
`4sigma and 2PI`
`5sigma and 1pi`

ANSWER :D
Discussion
50.

The number of sigma and pi bonds present in inorganic benzene

Answer»

`9sigma , 6PI`
`6 sigma , 3pi`
`9 sigma , 3pi`
`12 sigma , 3pi`

Solution : Inorganic BENZENE is `B_(3)N_(3)H_6`

It has `12 sigma,3pi`bonds
Discussion