datavorous/entrance-exam-dataset huggingface dataset:
In the figure there is a DC voltage regulator circuit, with a Zener breakdown voltage =6 V. If the unregulated input voltage varies between 10 V to 16 V, then what is the maximum Zener current?

Options:
A 1.5mA
B 7.5mA
C 3.5mA
D 2.5mA

The correct answer is:
3.5mA

Solution:
i1=64=1.5mA
Maximum current will be obtained for battery voltage

16V
i=16-62=5mA
i2(max)=5-1.5=3.5mA

Topic: Physics, Semiconductors, NEET
In the figure, two identical particles each of mass m are tied together with an inextensible massless string. This is pulled at its centre with a constant force F. If the whole system lies on a smooth horizontal plane, then the acceleration of each particle towards each other at the instant shown in the figure is

Options:
A 3 2 Fm
B 123Fm
C 23Fm
D 3Fm

The correct answer is:
123Fm

Solution:
2Tcos⁡30o=F
⇒ T=F2cos⁡30o=F3
Σ Fy=Tcos⁡60o=F23
Σ Fy=may
⇒ ay=F23m

Topic: Physics, Laws of Motion, NEET
In the figure, which of the diode is in reverse bias

Options:
A
B
C
D

The correct answer is:

Solution:
When N-type is at low potential and P-type is at the higher potential a diode is in forward bias.

P	N

a	+10	+5	forward biased

b	-10	0	reverse biased

c	-5	-12	forward biased

d	0	-10	forward biased

Topic: Physics, Semiconductors, NEET
In the final step of balancing, what does the verification of the equation involve?

Options:
A Checking the color change
B Balancing the number of atoms and charges
C Measuring the temperature change
D Calculating the reaction rate

The correct answer is:
Balancing the number of atoms and charges

Solution:
The passage mentions that the final verification of the equation involves checking that it is balanced in respect to the number of atoms and charges.

Topic: Chemistry, Redox Reactions, NEET
In the five-kingdom classification, which kingdom occupies an intermediate position from a phylogenetic point of view?

Options:
A Monera
B Protista
C Plantae
D None of these

The correct answer is:
Protista

Solution:
In the five kingdom classification protista occupies intermediate position from phylogenetic point of view. Because all multicellular eukaryotes like plants, fungi and animals are originated from unicellular eukaryotic protista.

Topic: Biology, Biological Classification, NEET
In the five-kingdom system of classification, which kingdom out of the following can include blue-green algae, nitrogen-fixing bacteria and methanogenic archaebacteria?

Options:
A Fungi
B Plantae
C Protista
D Monera

The correct answer is:
Monera

Solution:
Monera is the kingdom of all prokaryotes and includes bacteria, blue-green algae (cyanobacteria) and archaebacteria (a group of ancient bacteria). Protista includes unicellular and colonial eukaryotes; the important members are diatoms, dinoflagellates, euglenoids, moulds and protozoans. Fungi is the kingdom of multicellular or multinucleate heterophyllous and spore-producing eukaryotic organisms like Rhizopus mildews, mushroom etc. Kingdom Plantae includes all coloured multicellular photosynthetic organisms (plants).

Topic: Biology, Biological Classification, NEET
In the five-kingdom system of Whittaker, how many kingdoms are eukaryotes?

Options:
A 2
B 3
C 4
D 5

The correct answer is:
4

Solution:
Four kingdoms have eukaryotic organisms: Protista, Fungi, Plantae and Animalia.

Topic: Biology, Biological Classification, NEET
In the following
[Al(H2O)6]3+(p)+HCO3-(q)⇌[Al(H2O)5OH]2+(r)+H2CO3(s)
species behaving as Brosnted-Lowry acids are

Options:
A (p), (s)
B (q), (r)
C (q), (s)
D (p), (r)

The correct answer is:
(p), (s)

Solution:
For forward reaction [Al(H2O)6]3+ is an acid and for backward reaction H2CO3 is an acid.

Topic: Chemistry, Ionic Equilibrium, NEET
In the following change,
3Fe+4H2O→Fe3O4+4H2
If the atomic weight of iron is 56, then its equivalent weight will be

Options:
A 42
B 21
C 63
D 84

The correct answer is:
21

Solution:
3Fe0→Fe3+(8/3)+8e-
So E=Mn-factor=M8/3=56×38=21 .

Topic: Chemistry, Redox Reactions, NEET
In the following circuit of PN junction diodes D1, D2 and D3 are ideal then i is

Options:
A ER
B E2R
C 2E3R
D zero

The correct answer is:
ER

Solution:
Diodes D1 and D3 are forward biased and D2 is reverse biased so the circuit can be redrawn as follows.
âi=ER

Topic: Physics, Semiconductors, NEET
In the following circuit, the equivalent capacitance between terminal $A$ and terminal $B$ is :

Options:
A $1 \mu \mathrm{F}$
B $0.5 \mu \mathrm{F}$
C $4 \mu \mathrm{F}$
D $2 \mu \mathrm{F}$

The correct answer is:
$2 \mu \mathrm{F}$

Solution:
Given circuit is balanced Wheatstone bridge
$\begin{aligned} C_{A B} & =1+1 \\ & =2 \mu F\end{aligned}$

Topic: Physics, Capacitance, NEET, NEET 2024
In the following circuit, the output $\mathrm{Y}$ for all possible inputs $\mathrm{A}$ and $\mathrm{B}$ is expressed by the truth table.

Options:
A

B

C

D

The correct answer is:

Solution:
\(Y^{\prime}=\overline{A+B} . \quad Y=\overline{\overline{A+B}}=A+B\)
Truth table of the given circuit is given by
\(\begin{array}{|c|c|c|c|}
\hline A & B & Y^{\prime} & Y \\
\hline 0 & 0 & 1 & 0 \\
\hline 0 & 1 & 0 & 1 \\
\hline 1 & 0 & 0 & 1 \\
\hline 1 & 1 & 0 & 1 \\
\hline
\end{array}\)

Topic: Physics, Semiconductors, NEET, NEET 2007
In the following common emitter circuit, if Î²=100, VCE=7 V, RC=2 kÎ© and VBE is negligible, then IB is

Options:
A 0.01  mA
B 0.04  mA
C 0.02  mA
D 0.03  mA

The correct answer is:
0.04  mA

Solution:
V=VCE+ICRC
⇒15=7+IC×2×103 ⇒Ic=4 mA
∵β=ICIB ⇒IB=4100=0.04 mA

Topic: Physics, Semiconductors, NEET
In the following common emitter configuration, an NPN transistor with current gain Î²=100 is used. The output voltage of the amplifier will be

Options:
A 10 mV
B 0.1 V
C 1.0 V
D 10 V

The correct answer is:
1.0 V

Solution:
Voltage gain =Output voltageInput voltage
Vout = Vin × Voltage gain
Vout = Vin × Current gain × Resistance

= Vin×β×RoRi=10-3×100×101=1 V

Topic: Physics, Semiconductors, NEET
In the following compounds,

the correct decreasing order of acidity is

Options:
A III > IV > I > II
B I > IV > III > II
C II > I > III > IV
D IV > III > I > II

The correct answer is:
IV > III > I > II

Solution:
Acidic nature ∝ E.W.G. ∝1E.R.G.
As NO2 group is electron attracting while CH3 group is electron releasing group so NO2 increases acidic nature while CH3 decreases it.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
In the following compounds

the order of acidity is

Options:
A III > IV > I > II
B I > IV > III > II
C II > I > III > IV
D IV > III > I > II

The correct answer is:
IV > III > I > II

Solution:
Electron withdrawing group (-I, -M) like NO2 increase acidic nature while electron releasing group like CH3 decrease acidic nature so the order of acidity is IV > III > I > II.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
In the following compounds

The order of acidity is

Options:
A III > IV > I > II
B I > IV > III > II
C II > I > III > IV
D IV > III > I > II

The correct answer is:
IV > III > I > II

Solution:
-NO2 is an electron attracting group whereas -CH3 is an electron releasing group. An electron attracting substituent tends to disperse the negative charge of phenoxide ion and thus makes it more stable. This in turn increases the acidity of phenol. The substituent in Para-position is more effective than in meta-position as the former involves a resonating structure bearing negative charge on the carbon attached to electron with drawing substituent.
An electron releasing substituent tends to increase the negative charge of peroxide ion and thus makes it more unstable. This, in turn, decreases the acid strength of phenol.

Topic: Chemistry, General Organic Chemistry, NEET
In the following diagram of the lac operon, which is an operon for inducible enzymes, identify the components and enzymes.

Options:
A X= Repressor, Y= Inducer , E1=B-galactosidase E2= Permease, E3= Transacetylase
B X= Inducer , Y= Repressor, E1=B-galactosidase E2= Permease, E3= Transacetylase
C X= Repressor, Y= Inducer , E1=B-galactosidase E2= Transacetylase, E3= Permease
D X= Repressor , Y= Inducer , E1=Permease ,E2= Transacetylase , E3= B galactosidase

The correct answer is:
X= Repressor, Y= Inducer , E1=B-galactosidase E2= Permease, E3= Transacetylase

Solution:
The lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and some other enteric bacteria. It has three adjacent structural genes, lacZ, lac Y, and lac A. With lactose in the cell, inducer (Y) lactose binds to the repressor (X). This causes a structural change in the repressor, and it loses its affinity for the operator. Thus, RNA polymerase can then bind to the promoter and transcribe the structural genes. E1, E2 ,E3 represent B galactosidase, permease and transacetylase (they are synthesized from structural genes, lacZ, lacY, and lac A, respectively)

Topic: Biology, Molecular Basis of Inheritance, NEET
In the following diagram showing axon terminal and synapse, A, B, C, D and E respectively represent:

Options:
A axon terminal, synaptic cleft, synaptic vesicles, neurotransmitters and receptors
B synaptic cleft, synaptic vesicles, axon terminal, neurotransmitters and receptors
C axon terminal, synaptic vesicles, synaptic cleft, receptors and neurotransmitters
D synaptic cleft, axon terminal, synaptic vesicles, neurotransmitters and receptors

The correct answer is:
axon terminal, synaptic vesicles, synaptic cleft, receptors and neurotransmitters

Solution:
Chemical conduction takes place between the two neurons i.e. between Axon terminal of one neuron and dendrite or cyton of other neuron. This takes place through formation of cleft i.e. space between the two structures as neurotransmitters are released in that space. The figure is about a chemical synapse. Thus ‘A’ represents axon terminal. This forms the presynaptic membrane. This contains vesicles that are filled with neurotransmitters. Thus ‘B’ represents the vesicles. ‘C’ is the space and thus it is the cleft where release of neurotransmitters will take place when impulse has reached. ‘D’ is the part present after the synapse i.e. it is the post synaptic membrane which contains receptors. ‘E’ are released in the cleft and thus these are the neurotransmitters.

Topic: Biology, Neural Control and Coordination, NEET
In the following figure, what does Y and X represent?

Options:
A X is % saturation of haemoglobin with carbon monoxide and Y is Partial pressure of Oxygen
B X is % saturation of haemoglobin with oxygen and Y is Partial pressure of carbon dioxide
C X is % saturation of haemoglobin with carbon monoxide and Y is Partial pressure of carbon dioxide
D X is % saturation of haemoglobin with oxygen and Y is Partial pressure of Oxygen

The correct answer is:
X is % saturation of haemoglobin with oxygen and Y is Partial pressure of Oxygen

Solution:
[D]X is % saturation of haemoglobin with oxygen and Y is Partial pressure of Oxygen

Topic: Biology, Breathing and Exchange of Gases, NEET
In the following flowchart about protein digestion, P, Q, R and S are enzymes.

The correct information of enzymes P, Q, R and S is

Options:
A P: Produced by intestine as a proenzyme stage and is activated at alkaline pH
Q: Produced by pancreas as acts a proenzyme and is activated by an intestinal enzyme
R: Produced by stomach as a proenzyme stage and is activated at acidic pH
S: Produced by pancreas in an active state
B P: Produced by stomach as a proenzyme stage and is activated at acidic pH
Q: Produced by pancreas as acts a proenzyme and is activated by an intestinal enzyme
R: Produced by pancreas in an active state
S: Produced by intestine in an active state
C P: Produced by stomach as a proenzyme and is activated at acidic pH
Q: Produced by pancreas as a proenzyme and is activated by an intestinal enzyme
R: Produced by intestine in an active state
S: Produced by intestine in an active state
D P: Produced by stomach as a proenzyme stage and is activated at acidic pH
Q: Produced by pancreas as a proenzyme and is activated by an intestinal enzyme
R: Produced by intestine as a proenzyme and is activated by Q
S: Produced by intestine in an active state

The correct answer is:
P: Produced by stomach as a proenzyme and is activated at acidic pH
Q: Produced by pancreas as a proenzyme and is activated by an intestinal enzyme
R: Produced by intestine in an active state
S: Produced by intestine in an active state

Solution:
P- pepsin produced by stomach as pepsinogen. It is activated at acidic pH. It converts proteins into proteoses and peptones. Q- Trypsin or chymotrypsin produced by pancreas as trypsinogen or chymotrypsinogen. Trypsin is activated by enterokinase from the intestine. It can convert peptones and proteoses to polypetides. R- Aminopeptidase produced intestine in an active form. R could also be carboxypeptidase produced by pancreas as procarboxypeptidase. Both of them can convert polypetides to dipeptides. In this contect it is aminopeptidase. S is dipeptidase produced by intestine in an active form. It converts dipeptides to amino acids

Topic: Biology, Digestion and Absorption, NEET
In the following graph of Maxwell-Boltzmann distribution of molecular velocities. Which of the following is the correct order of temperature?

Options:
A T1<T2<T3
B T3<T2<T1
C T2<T1<T3
D None of these

The correct answer is:
T1<T2<T3

Solution:
The peak represents UMPS as U MPS ∝ T , the graph a T3 has maximum UMPS, hence T3 is the highest temperature.

Topic: Chemistry, States of Matter, NEET
In the following human pedigree, the filled symbols represents the affected individuals. Identify the type of given pedigree.

Options:
A X-linked recessive
B Autosomal recessive
C X-linked dominant
D Autosomal dominant

The correct answer is:
Autosomal recessive

Solution:
The given pedigree represents the inheritance of the Autosomal recessive trait because the unaffected parents have an equally affected son and daughter. The genotype of the individual in the family can be represented as:
`

Topic: Biology, Principles of Inheritance and Variation, NEET
In the following human pedigree, the filled symbols represents the affected individuals. Identify the type of given pedigree.

Options:
A X-linked recessive
B Autosomal recessive
C X-linked dominant
D Autosomal dominant

The correct answer is:
Autosomal recessive

Solution:
The given pedigree represents the inheritance of the Autosomal recessive trait because the unaffected parents have an equally affected son and daughter. The genotype of the individual in the family can be represented as:
`

Topic: Biology, Principles of Inheritance and Variation, NEET, NEET 2015 (Phase 2)
In the following, in each set, a conservation approach and an example of a method of conservation are given
(a) In situ conservation-Biosphere Reserve
(b) Ex situ conservation-Sacred groves
(c) In situ conservation-Seed bank
(d) Ex situ conservation-Cryopreservation

Select the option with a correct match of approach and method:

Options:
A (a) and (c)
B (a) and (d)
C (b) and (d)
D (a) and (b)

The correct answer is:
(a) and (d)

Solution:
In-situ conservation: The In–situ strategies emphasis protection of whole ecosystem. Examples are national parks, wild life sancturies, biosphere reserves and sacred grooves.

Ex-situ conservation: In this type of conservation strategies, threatened animals and plants are taken out from their natural habitat and placed in special setting where they can be protected and given special care. Examples are seed bank, cryopreservation, botanical gardens, and zoological parks.

Topic: Biology, Biodiversity and its Conservation, NEET, NEET 2020 (Phase 2)
In the following network, the current flowing through 15 Î© resistance is

Options:
A 0.8 A

B 1.0 A

C 1.2 A

D 1.4 A

The correct answer is:
1.2 A

Solution:
I 1 + I 2 =2.1A â¦.(1)
18 I 1 =24 I 2 â¦(2)
â 3 I 1 =4 I 2 =4( 2.1â I 1 )
I 1 = 8.4 7 =1.2 A

Topic: Physics, Current Electricity, NEET
In the following network, the potential at O is

Options:
A 4 V
B 3 V
C 6 V
D 4.8 V

The correct answer is:
4.8 V

Solution:
Let the potential at O is V0.
Application of Kirchhoff's first law at junction O gives
8-V02=V0-44+V0-22
=V0-4+2V0-44
48-V02=V0-4+2V0-4
16-2V0=3V0-8
16+8=5V0
V0=245=4.8 V

Topic: Physics, Current Electricity, NEET
In the following nuclear reaction x stands for n→p+e-+x

Options:
A α -particle
B positron
C nutrino
D antinutrino

The correct answer is:
antinutrino

Solution:
With electron always Antinutrino is emitted

Topic: Physics, Nuclear Physics, NEET
In the following pair of halogen compounds, which compound undergoes faster SN1 reaction?

Options:
A Both the compounds have same rate
B (ii)
C Neither of the compounds undergo SN2 reaction
D (i)

The correct answer is:
(i)

Solution:
Correct Option is : (D)
(i)

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
In the following pair of halogen compounds, which compound undergoes faster SN1 reaction?

Options:
A Both the compounds have same rate
B (ii)
C (i)
D Neither of the compounds undergo SN2 reaction

The correct answer is:
(i)

Solution:
Correct Option is : (C)
(i)

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
In the following pair of halogen compounds, which would undergo SN2 reaction faster?

Options:
A n-Butyl chloride
B n-Butyl iodide
C Both of them undergo SN2 reaction at the same rate
D Neither of them undergo SN2 reaction

The correct answer is:
n-Butyl iodide

Solution:
Correct Option is : (B)
n-Butyl iodide

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
In the following palindromic base sequences of DNA, which one can be cut easily by particular restriction enzyme?

Options:
A

5' G A A T T C 3'

3' C T T A A G 5'

B

5' C T C A G T 3'

3' G A G T C A 5'

C

5' G T A T T C 3'

3' C A T A A G 5'

D

5' G A T A C T 3'

3' C T A T G A 5'

The correct answer is:

5' G A A T T C 3'

3' C T T A A G 5'

Solution:
A sequence of base pairs that reads same on the two strands when orientation of reading is kept the same, is called a palindromic nucleotide sequence in the DNA.

For example restriction enzyme EcoRI recognises a particular palindromic sequence:-

5' G A A T T C 3'

3' C T T A A G 5'

Topic: Biology, Biotechnology - Principles and Processes, NEET, NEET 2022 (Phase 1)
In the following reaction,

Options:
A

B

C

D

The correct answer is:

Solution:

Topic: Chemistry, Hydrocarbons, NEET, NEET 2012 (Screening)
In the following reaction,
2SO2(g)+O2(g)→2SO3(g)
The rate of formation of SO3 is 100 g min-1 . Hence, the rate of disappearance of CO2 is

Options:
A 50 gmin-1
B 20 gmin-1
C 100 gmin-1
D 200 gmin-1

The correct answer is:
20 gmin-1

Solution:
In the reaction
2 SO 2 g + O 2 g 1mol 32g â 2 SO 3 g 2mol 160g
Hence, 160 g of SO3 is formed by 32 g of O2
So 100 g of SO3 will be formed =32160Ã100= 20 g of O2
So rate of disappearance of O2=20 g min-1 .

Topic: Chemistry, Chemical Kinetics, NEET
In the following reaction A is

Options:
A
B
C
D

The correct answer is:

Solution:
Here A is cyclohexane and the reaction sequence is as follows

Topic: Chemistry, Aldehydes and Ketones, NEET
In the following reaction
Aldehyde + Alcohol →HCl Acetal

Aldehyde	Alcohol

HCHO	BuOH

CH3CHO	MeOH

The best combination is

Options:
A HCHO and MeOH
B HCHO and BuOH
C CH3CHO and MeOH
D CH3CHO and BuOH

The correct answer is:
HCHO and MeOH

Solution:
Rate of nucleophilic addition on carbonyl carbon ∝1sterichinderance
As t-Butanol can show formation of carbocation in acidic medium so it will not be able to behave as nucleophile.

Topic: Chemistry, Aldehydes and Ketones, NEET
In the following reaction,

CH3COCl â BaSO4 Pd/H2X

Identify X out of the following

Options:
A Acetaldehyde
B Propionaldehyde
C Acetone
D Acetic anhydride

The correct answer is:
Acetaldehyde

Solution:
CH 3 −COCl acetyl chloride  +  H 2 → Pd-BaSO 4 CH 3 CHO acetaldehyde  + HCl
This reaction is called Rosenmund's reaction.

Topic: Chemistry, Aldehydes and Ketones, NEET
In the following reaction correct change in phosphorus is explained by, 4P+3KOH+3H2O→3KH2PO2+PH3

Options:
A P is oxidized as well as reduced
B P is oxidised only
C P is reduced only
D None of these

The correct answer is:
P is oxidized as well as reduced

Solution:
P is oxidized as well as reduced, its oxidation number changes from 0 (P-atom) to +1 (KH2PO2) and -3(PH3) .

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
In the following reaction
HCO3-+H2O⇌CO32-+H3O+
Which two substances are Bronsted base?

Options:
A CO32- and H3O+
B HCO3- and H3O+
C HCO3- and CO32-
D CO32- and H2O

The correct answer is:
CO32- and H2O

Solution:
Here CO32- and H2O are Bronsted bases as water accept H+ and CO32- is the conjugate base of HCO3- and as the reaction is reversible so CO32- is accepting H+ also.
HCO3-+H2O⇌CO32-+H3O+

Topic: Chemistry, Ionic Equilibrium, NEET
In the following reaction product ' $\mathrm{P}$ ' is:

Options:
A $\mathrm{RCH}_2 \mathrm{OH}$
B $\mathrm{RCOOH}$
C $\mathrm{RCHO}$
D $\mathrm{RCH}_3$

The correct answer is:
$\mathrm{RCHO}$

Solution:
The given reaction represents Rosenmund's reaction.
Mechanism of Rosenmund's reaction

Topic: Chemistry, Aldehydes and Ketones, NEET, NEET 2002
In the following reaction:
Product ' $\mathrm{P}$ ' will not give

Options:
A Tollen's reagent test
B Brady's reagent test
C Victor Meyer test
D Iodoform test

The correct answer is:
Victor Meyer test

Solution:

Topic: Chemistry, Alcohols Phenols and Ethers, NEET, NEET 2013 (Karnataka)
In the following reaction sequence, the correct structures of E, F and G are

â Heat [ E ] â NaOH I 2 [ F ]+[ G ]

[ * implies 13 C labelled carbon ]

Options:
A

B

C

D None of these

The correct answer is:

Solution:

Topic: Chemistry, Carboxylic Acid Derivatives, NEET
In the following reaction,
the compound Z is

Options:
A benzoic acid
B benzaldehyde
C acetophenone
D benzene

The correct answer is:
benzaldehyde

Solution:

Topic: Chemistry, Aldehydes and Ketones, NEET
In the following reaction,

The major product obtained is

Options:
A
B
C
D

The correct answer is:

Solution:
It is a case of free radical substitution reaction (Halogination) in which rate of reaction and product formation depend upon stability of free radical formed. In option (D) tertiary free radical is formed so product in option (D) is major.

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
In the following reaction,
the number of sigma( $\sigma$ ) bonds present in the product $A$ is

Options:
A 21
B 9
C 24
D 18

The correct answer is:
21

Solution:
Key Idea Single bond $=1 \sigma$, Double bond $=1 \sigma, 1 \pi$; Triple bond $=1 \sigma$ and $2 \pi$.
Alkynes form aromatic compounds when their vapours are passed over red hot copper or iron tubes.
The number of sigma $(\sigma)$ bonds present in the product (A) is 21.

Topic: Chemistry, Hydrocarbons, NEET, NEET 2019 (Odisha)
In the following reaction, the product (A)

Options:
A
B
C
D

The correct answer is:

Solution:
It is an electrophilic substitution reaction.

In the given coupling reaction, compound 1is yellow dye represented by the structure given in option 4.
Coupling reaction of aniline takes place at the para-position to NH2 group in the benzene nucleus gives azodye.

Topic: Chemistry, Amines, NEET, NEET 2014
In the following reaction, the product (P)

Options:
A
B
C
D

The correct answer is:

Solution:
This is an example of electrophilic substritituion reaction [coupling reaction]

Topic: Chemistry, Amines, NEET
In the following reaction, the product ‘R’ is

CaC 2 → H 2 O P → hot iron Q → AlCl 3 CH 3 Cl R

Options:
A toluene
B n- propylbenzene
C ethylbenzene
D benzene

The correct answer is:
toluene

Solution:
Here the product ‘R’ is Toluene formed as follows

Topic: Chemistry, Hydrocarbons, NEET
In the following reaction

the structure of the major product ‘X’ is

Options:
A
B
C
D

The correct answer is:

Solution:
As due to presence of lone pair of electrons on nitrogen atom, it will activate the ring and it will stabilize intermediate cation at o- and p- positions so here electrophile NO 2 + attack para position which is better than ortho due to less steric hindrance. As CO group is ring deactivating so ortho ,para with respect to it are ignored.

Topic: Chemistry, Amines, NEET