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.

Plaster of paris is hardened by:

Answer»

GIVING off `CO_2`
CHANGING into `CaCO_3`
UNITING with water
Giving out water

Answer :C
Discussion
2.

Plaster of paris is :

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`CaSO_(4)`
`CaSO_(4)*7H_(2)O`
`2CaSO_(4)*H_(2)O`
`CaSO_(4)*2H_(2)O`

ANSWER :C
Discussion
3.

Plaster of paris in contact with water sets into a hard mass. The composition of hard mass is:

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`CaSO_4.H_2O`
`CaC_2 and CO`
`CaSO_4 . 2H_2O`
`CaC_2 and CO_2`

ANSWER :C
Discussion
4.

Plants synthesise …………………… and ………………………… to protect then from being eaten away by insects and other animals.

Answer»


ANSWER :ALKALOIDS, biologically ACTIVE AMINES
Discussion
5.

Platinized asbestos used as a catalyst in the manufacture of H_2SO_4 is an example of:

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HETEROGENEOUS catalysis
Autocatalysis
Homogeneous catalysis
Induced catalysis

Answer :A
Discussion
6.

Plantfibres are

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PROTEIN FIBRES
CELLULOSE fibres
protein fibres
none of these

Answer :B
Discussion
7.

Plane polarized light.

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SOLUTION :A RAY of monochromatic light in which vibrations of the radiation WAVES take place only in one plane is called plane POLARIZED light.
Discussion
8.

Placedo' is often given to patients. It is

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A tonic
A BROAD spectrum antibiotic
A SUGAR pill
An antidepressant

Answer :C
Discussion
9.

Placedo' is often given to patients. It is :

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An ANTIDEPRESSANT
A BROAD spectrum ANTIBIOTIC
A sugar pill
A tonic

Answer :C
Discussion
10.

Placedo. is often given to patients. It is :

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An ANTIDEPRESSANT
A broad spectrum ANTIBIOTIC
A SUGAR pill
A tonic

Answer :C
Discussion
11.

Place the following alcohols in decreasing order of rate of dehydration with conc. H_2SO_4 . (1)CH_3CH_2CH(OH)CH_2CH_2CH_3 (2)(CH_3)_2C(OH)CH_2CH_2CH_3 (3)CH_3CH_2CH_2CH_2CH_2CH_2-OH (4)(CH_3)_2C(OH)CH(CH_3)_2

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4 gt 2 gt 1 gt 3
1 gt 2 gt 3 gt 4
4 gt 3 gt 2 gt 1
4 gt 3 gt 1 gt 2

Solution :The alcohol 4 and 2 are `3^@` alcohol but alcohol 4 gives more substituted alkene easily. Alcohol 1 is `2^@` alcohol and alcohol 3 is `1^@` alcohol. The RATE of DEHYDRATION of alcohol with CONCENTRATED `H_2SO_4` follows the ORDER `3^@ gt 2^@ gt 1^@`
Discussion
12.

Placebo is often given to patients it is

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A SUGAR PILL
Anti SEPTIC
Anti pyretic
Disinfectant

SOLUTION :PLACEBO is a sugar coated pill
Discussion
13.

pK_(a1) and pK_(a_(2)) of H_(2)CO_(3) are 6.38 and 10.26 respectively. The pH of 1 M and 0.1 M NaHCO_(3) are

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8.32,7.32
7.32,8.32
8.32,8.32
7.32,7.32

Solution :PH in this CASE is INDEPENDENT of CONCENTRATION.
Discussion
14.

pK_(a) values of two acids A and B are 4 and 5. The strengths of these two acids are related as

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ACID A is 10 times STRONGER than acids B
Strength of acid A : strength of acid B = 4:5
The STRENGTHS of the two acids can not be compared
Acid B is 10 times stronger than acid A

Solution :`pK_(a)` of acid A =4 , `pK_(a)` of acid B = 5
We KNOW that `pK_(a) = -log K_(a)`
`:.` Acid A `K_(a) = 10^(-4)`, Acid `B K_(a) = 10^(-5)`
Hence A is ten times stronger than that of B.
Discussion
15.

pk_a values of two acids A and B are 4 and 5. The strength of these two acids are related as

Answer»

acid A is 10 TIMES STRONGER than acid B
STRENGTH of acid A: strength of acid B = 4:5
the strength of TWO acids cannot be compared
acid B is 10 times stronger than acidA

Solution :`K_a"of"A=10^(-4) `
`K_a"of"B=10^(-5)`
i.e,A is10timesstrongerthanB.
Discussion
16.

P^(ka) values of different hydro halic acids in random is 3.2, 9.5 -10 and -7. So In aq. Solution HCl has an Ka value

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`10^(6)`
`10^(7)`
`10^(8)`
`10^(14)`

Answer :B
Discussion
17.

pK_(a)value of 4-nitrobenzoic acid is lower than that of benzoic acid. Why ?

Answer»

Solution :`pK_(a)`VALUE of 4-nitrobenzoic acid is lower than benzoic acid is DUE to `e^(–)`withdrawing nature of —`NO_(2)`attach at PARA position of BENZENE due to which tendency to loose ` H^(+)`ion increases and acidic character increases.
Discussion
18.

P^(ka) value of least for

Answer»




ANSWER :C
Discussion
19.

pK_(a) value of the strongest acid among the following is

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`3.0`
`4.5`
`1.0`
`2.0`

SOLUTION :SMALLER the `pK_(a)` value than STRONGER the acid.
Discussion
20.

pK_(a) of weak acid (HA) and pK_(b) of a weak base (BOH) are 3.2 and 3.4, respectively. The pH of their salt (AB) solution is

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6.9
`7.0`
`1.0`
7.2

Solution :Salt of weak ACID and weak base
`PH = (1)/(2)(pk_(w)+ pK_(a) - pK_(b))`
`= (1)/(2)(14 + 3.2 - 3.4)`
= 6.9
Discussion
21.

pKa of waek acid is 3.0. Effective range of a buffer of HA and A^(-) is about pH :-

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3 to 4
3 to 6
2 to 3
2 to 4

Answer :4
Discussion
22.

pK_(a) of chloroacetic acid is lower than pK_(a) of acetic acid. Explain.

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Solution :`pK_(a)` of chloroacetic acid is lower than `pK_(a)` of acetic acid. This MEANS, chloroacetic acid is a stronger acid than acetic acid. This may be explained on the basis of the following two reasons:
(i) DUE to -I-effect of Cl atom, the electron density in the O-H bond in chloroacetic acid is much lower than due to +I-effect of `CH_(3)` GROUP in acetic acid. as a result, O-H bond in chloroacetic acid is much weaker than in acetic acid and hence loses a proton more easily acid.

(ii) Due to -I-effect of Cl, dispersal of the -ve charge occurs in chloroacetate ion but due to +I-effect of `CH_(3)` group, intensification of -ve charge occurs in acetate ion. in other words, chloroacetate ion is much more stable than acetate ion.
Discussion
23.

pK_(a) of acetic acid is 4.74. The concentration of CH_(3)COONa is 0.01 M. The pH of CH_(3)COONa is

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8.37
4.37
4.74
0.474

Solution :`pH = 7 + (1)/(2)[pK_(a) + log C] = 7 + (1)/(2)[4.74 + log 10^(-2)]`
`= 7 + (1)/(2)[4.74 -2] = 7+ (2.74)/(2) = 8.37`
Discussion
24.

pK_(a) of a weak acid is defined as

Answer»

`log_(10)K_(a)`
`(1)/(log_(10) K_(a))`
`log_(10). (1)/(K_(a))`
`-log_(10).(1)/(K_(a))`

ANSWER :C
Discussion
25.

pK_(a) for acetic acid is 4.74. What should be the ratio of concentration of acetic acid and acetate ions to has a solution with pH = 5.74 ?

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`1 : 10`
`10 : 1`
`1 : 1`
`2 : 1`

SOLUTION :, (RETENTION of CONFIGURATION)
Discussion
26.

pK_(a) and K_(a) of an acid are connected by the relation.......

Answer»


ANSWER :`pK_(a)=-"LOG"K_(a)`
Discussion
27.

pK_a for acetic acid is 4.74. The concentration of CH_3COONa is 0.01 M. The pH of CH_3COONa is…….

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3.37
4.37
4.74
0.474

Solution :`[H^+]=C.a SQRT(K_a.C)`
`pH=-LOG(K_a.C)^(1/2)`
`=1/2[-log K_a-log c]`
`=1/2[4.74-log 10^-2]`
`=1/2[4.74+2]=3.37`
`pH=3.37`
Discussion
28.

pK_(a) and K_(a) of an acid are connected by the relation ______.

Answer»

SOLUTION :`pK_(a)=-logK_(a)`.
Discussion
29.

pKa values of two acids A and B are 4 and 5. The strengths of these two acids are related as

Answer»

the strengths of the TWO acid cannot be compared
acid B is 10 TIMES stronger than acid A
acid A is 10 times stronger than acid B
STRENGTH of acid A: strength of acid `B= 4 : 5`

Solution :`pK_(a (A)) = -log K_(a (A)) = 10^(-4)`
`pK_(a (B)) = - log K_(a) (B) = 10^(-5)`
By comparing, `K_(a(A)) = 10K_(a(B))`
Discussion
30.

pK, value of trifluoroacetic acid, benzoic acid and acetic acid are respectively

Answer»

4.76, 4:19 and 0:23
4-19, 4-76 and 0-23
0-23, 4-76 and 4-19
0:23, 4-19 and 4.76

Answer :D
Discussion
31.

Piperidine is a secondary amine, which is subjected to Hofmann elimination. The alkene formed as a final product is

Answer»

1, 3-butadiene
1,4-pentadiene
1, 3-butadiyne
1, 2-pentadiene

Solution :
Discussion
32.

Pithchblends is the main source of :

Answer»

U
Ce
Th
Mg

Answer :A
Discussion
33.

Piperidine is

Answer»

HOMOCYCLIC COMPOUND
Heterocylic AROMATIC compound
Heterocyclic alicyclic compound
Acyclic compound

Solution :, PIPERIDINE is heterocyclic, alicylic compound.
Discussion
34.

Pinacol is converted in to pinacolone by

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REARRANGMENT
oxidation
reduction
hydrolysis

ANSWER :A
Discussion
35.

Pinacole is:

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2,3-dimethyl-2,3-butanediol
3,3-methyl-2 propanone
3-methyl butan-2-ol
None

Answer :A
Discussion
36.

Pig iron is manufactured using :

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An ELECTRIC FURNACE
A BLAST furnace
An open hearth furnace
None of these

ANSWER :B
Discussion
37.

Pig iron is manufactured by:

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An ELECTRIC furnace
A blast furnace
An open heart furnace
None of these

Answer :B
Discussion
38.

Pig iron is converted into steel by decreasing the amount of carbon contained in it, in a:

Answer»

BLAST furnace
Pyrite burner
Bessemer's converter
None of these

ANSWER :C
Discussion
39.

Pig iron__________.

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is the iron containing the carbon and other impurities
is a PURE FORM of iron
is similar to wrought iron
is similar to steel

Answer :A
Discussion
40.

Pig iorn has more or less same composition as that of

Answer»

CAST iron
steel
wrought iron
All

Answer :1
Discussion
41.

Pig iron :

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Contains CARBON and other impuriies
Is PURE from of iron
Is same as WROUGHT iron
Is same as STEEL

Answer :A
Discussion
42.

Picric acid is (at 25^(@) C)

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A WHITE solid
A COLOURLESS liquid
A gas
A BRIGHT yellow solid

Answer :C
Discussion
43.

Pieces of wood burn faster than a log of wood of the same mass because

Answer»

surface AREA of log of wood is larger and needs more time to burn
pieces of wood have larger surface area
all pieces of wood CATCH FIRE at the same time
log of wood has higher density than pieces of the same wood

Solution :More the surface area of REACTANT, more will be the rate of reaction.
Discussion
44.

Picric acid is obtained by the nitration of

Answer»

cumene
phenol
methanol
ethanol

Answer :B
Discussion
45.

Picric acid is…

Answer»

Trinitro TOLUENE
Trinitro aniline
Trinitro PHENOL
None of these

Solution :
Trinitro phenol (PICRIC ACID)
Discussion
46.

Picric acid is-

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2-ntirophenol
4-nitrophenol
2,4-dinitrophenol
2,4,6-trinitrophenol

Solution :2,4-dinitrophenol
Discussion
47.

Picric acid contain

Answer»

2-nitro groups
3-nitro groups
2-nitrite groups
3-nitrite groups

Answer :B
Discussion
48.

Pickout the correct statements:

Answer»

Negative `BETA`-decay decreases the proportion of neutrons and INCREASES the proportion of proton
Positive `beta`-decay increases the proportion of neutrons and decreases the proportion of proton
`K`-electron capture increases the proportion of neutrons and increases the proportion of proton.
Positrons and ELECTRONS quickly unite to produce photons.

Answer :A, B, D
Discussion
49.

Pickup the correct formula of potash alum.

Answer»

`K_(2)SO_(4). Al_(2)(SO_(4))_(3).24H_(2)O`
`K_(2)SO_(4).Al_(2)(SO_(4))_(2).24H_(2)O`
`K_(2)SO_(4).Al_(2)(SO_(4))_(3).12H_(2)O`
`K_(2)SO_(4).Al(SO_(4))_(3).12H_(2)O`

ANSWER :A
Discussion
50.

Pickles have a long shelf life and do not get spoiled for months, why?

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Solution :Plenty of salt and cover of OIL act as preservatives. These food preservatives prevent spoilage of food DUE to microbial growth. Salt and oil do not allow moisture and AIR to ENTER the material and hence bacteria cannot THRIVE on them. Therefore, pickles do not set spoiled for month together.
Discussion