List of top Questions asked in JEE Main- 2023

Let the lines l₁ :  \(\frac{x+5}{3} =\frac{y+4}{1}=\frac{z−α}{−2}\)  and l₂ :3x+2y+z–2=0=x–3y+2z-13 be coplanar. If the point P(a, b, c) on l₁ is nearest to the point Q(-4,-3, 2), then |a| + |b|+|c| is equal to

Let a, b, c be three distinct real numbers, none equal to one. If the vectors \(a\hat{i}+\hat{j}+\hat{k},\hat{i}+b\hat{j}+\hat{k}\) and \(\hat{i}+\hat{j}+c\hat{k}\) are coplanar, then \(\frac{1}{1-a}+\frac{1}{1-b}+\frac{1}{1-c}\) is equal to 

(S1): (p⇒q)∧(p∧((~q)) is a contradiction and
(S2): (p∧q)v((~q)v((~p)∧ q)v (p∧(~q))v((~p)∧ (~q)) is a tautology

Match List I with List II

	List I		List II
A	Spring constant	I	[T-1]
B	Angular speed	II	[MT-2]
C	Angular momentum	III	[ML2]
D	Moment of Inertia	IV	[ML2T-1]

Choose the correct answer from the options given below:

Given below are two statements:
Statement I: A truck and a car moving with same kinetic energy are brought to rest by applying brakes which provide equal retarding forces. Both come to rest in equal distance. 
Statement II : A car moving towards east takes a turn and moves towards north, the speed remains unchanged. The acceleration of the car is zero.  
In the light of given statements, choose the most appropriate answer from the options given below. 

The amplitude of 15sin(1000πt) is modulated by 10sin(4πt) signal. The amplitude modulated signal contains frequency (ies) of
(A) 500 Hz  
(B) 2 Hz  
(C) 250 Hz  
(D) 498 Hz  (E) 502 Hz 
Choose the correct answer from the options given below: 

An engine operating between the boiling and freezing points of water will have  
1. efficiency more than 27%  
2. efficiency less than the efficiency a Carnot engine operating between the same two temperatures.  
3. efficiency equal to 27%  
4. efficiency less than 27%  

A wire of resistance 160 Ω is melted and drawn in wire of one-fourth of its length. The new resistance of the wire will be

A particle is thrown vertically upward with initial velocity of 150 m/s. Find the ratio of its speed at t = 3 seconds and t = 5 seconds. is \(\frac{x+1}{x}\) the value of x is___. (take g = 10 m/s2)

Three force F₁ = 10N, F₂ = 8 N, F₃ = 6N are acting on a particle of mass 5 kg. The forces F₂ and F₃ are applied perpendicular so that particle remains at rest. If the force F₁ is removed, then the acceleration of the particle is

An ice cube has a bubble inside. When viewed from one side the apparent distance of the bubble is 12 cm. when viewed from the opposite side, the apparent distance of the bubble is observed as 4 cm. If the side of the ice cube is 24 cm, the refractive index of the ice cube is

A proton and an α-particle are accelerated from rest by 2V and 4V potentials, respectively. The ratio of their de-Broglie wavelength is

A 12.5 eV electron beam is used to bombard gaseous hydrogen at room temperature. The number of spectral lines emitted will be

In an n-p-n common emitter (CE) transistor the collector current changes from 5 mA to 16 mA for the change in base current from 100 μA and 200 μA, respectively. The current gain of transistor is______.

A metal chloride contains 55.0% of chlorine by weight. 100 mL vapours of the metal chloride at STP weigh 0.57 g. The molecular formula of the metal chloride is (Given: Atomic mass of chlorine is 35.5u)

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: In the Ellingham diagram, a sharp change in slope of the line is observed for Mg → MgO at ~ 1120°C 
Reason R: There is a large change of entropy associated with the change of state. 
In the light of the above statements, choose the correct answer from the options given below : 

Match List I with List II

	List I -complex		List II-CFSE
A	[Cu(NH3)6]2+	I	-6.0
B	[Ti(H2O)6]3+	II	-2.0
C	[Fe(CN)6]3-	III	-1.2
D	[NiF6]4-	IV	-0.4

Choose the correct answer from the options given below:

Correct statements for the given reaction are:

A. Compound 'B' is aromatic 
B. The completion of above reaction is very slow 
C. 'A' shows tautomerism 
D. The bond lengths C-C in compound B are found to be same 
Choose the correct answer from the options given below

The two products formed in above reaction are

Match List I with List II

	List I-Examples		List II-Type
A	2-Chloro-1, 3-butadiene	I	Nylon 2-nylon 6
B	Nylon 2-nylon 6	II	Synthetic Rubber
C	Polyacrylonitrile	III	Polyester
D	Dacron	IV	Addition Polymer

Choose the correct answer from the options given below:

The volume (in mL) of 0.1 M AgNO₃ required for complete precipitation of chloride ions present in 20 mL of 0.01 M solution of [Cr(H₂O)₅CI]Cl₂ as silver chloride is___

30.4 kJ is required to melt one mole of sodium chloride. The entropy change during melting is 28.4 JK-1 mol-1 . atm The melting point of sodium chloride Calculate is ___ K(Nearest Integer).

For a reversible reaction A ⇌ B, the ΔH_{forward reaction} = 20 kJ mol^-1. The activation energy of the uncatalysed forward reaction is 300 kJ mol^-1. When the reaction is catalysed keeping the reactant concentration same, the rate of the catalysed forward reaction at 27°C is found to be same as that of the uncatalysed reaction at 327°C. The activation energy of the cataysed backward reactoion is ____ kJ mol^-1.

20 mL of 0.5 M NaCl is required to coagulate 200 mL of As2S3 solution in 2 hours. The coagulating value of NaCl is____

The total change in the oxidation state of manganese involved in the reaction of KMnO₄ and potassium iodide in the acidic medium is______