List of top Questions asked in JEE Main

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Phenolphthalein is a pH dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium.
Reason R: Phenolphthalein is a weak acid. It doesn’t dissociate in basic medium.
In the light of the above statements, choose the most appropriate answer from the options given below.

Then the number of elements in the set {(n, m) : n, m ∈ { 1, 2….., 10} and nAn + mBm = I} is _______.

Let A = {1, 2, 3, 4, 5, 6, 7} and B = {3, 6, 7, 9}. Then the number of elements in the set {C ⊆ A :Cߏ∩B ≠ φ} is _____________.
Let the matrix \(A=\begin{bmatrix}0 & 1 & 0 \\ 0 & 0 & 1 \\ 1 & 0 & 0\end{bmatrix}\) and the matrix \(B_0=A^{49}+2 A^{98}\) If \(B_n=\text{Adj}\left(B_{n-1}\right)\) for all \(n \geq 1\), then \(\text{det}\left( B _4\right)\) is equal to :
Which of the following statement is correct ?

Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R. 

Assertion A: Two identical balls A and B thrown with same velocity ’u’ at two different angles with horizontal attained the same range R. If A and B reached the maximum height h1 and h2 respectively, then 

\(R=\sqrt{4ℎ1ℎ2}.\)

Reason R: Product of said heights.

\(h_1h_2=(\frac{u^2sin^2θ}{2g}).(\frac{u^2cos^2θ}{2g})\)

The graph between \(\frac 1u\) and \(\frac 1v\) for a thin convex lens in order to determine its focal length is plotted as shown in the figure. The refractive index of lens is 1.5, and its both the surfaces have the same radius of curvature R. The value of R will be______cm.
(where u = object distance, v = image distance)
The graph between 1/u and 1/v for a thin convex lens
Bonding in which of the following diatomic molecule(s) become(s) stronger, on the basis of MO Theory, by removal of an electron?
(A) NO
(B) N2
(C) O2
(D) C2
(E) B2
Choose the most appropriate answer from the options given below :

Outermost electronic configurations of four elements A,B,C,D are given below:
(A) 3s2 (B) s23p1 (C) 3s23p3 (D) 3s23p4
The correct order of fist ionization enthalpy for them is:

For the reaction H2F2(g) → H2(g) + F2(g), ΔU = –59.6 kJ mol–1 at 27°C. The enthalpy change for the above reaction is (–) _______ kJ mol–1 [nearest integer] Given: R = 8.314 J K–1 mol–1.
The correct decreasing order of priority of functional groups in naming an organic compound as per IUPAC system of nomenclature is
The plot of pH-metric titration of weak base NH4OH vs strong acid HCl looks lie:
Match List-I with List -II
List - IList - II
(A) \(ψ_{MO}=ψ_A-ψ_B\)(I) Dipole moment
(B) \(µ=Q×r \)(II) Bonding molecular orbital
(C) \(\frac{N_b-N_a}2\)(III) Anti-bonding molecular orbital
(D) \(ψ_{MO}=ψ_A+ψ_B\)(IV) Bond order

Choose the correct answer from options given below:
Arrange the following in increasing order of their covalent character. 
A. \(CaF_2\) 
B. \(CaCl_2\) 
C. \(CaBr_2\) 
D. \(Cal_2\)
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R) :
Assertion (A) : Dissolved substances can be removed from a colloidal solution by diffusion through a parchment paper.
Reason (R) : Particles in a true solution cannot pass through parchment paper but the colloidal particles can pass through the parchment paper.
In the light of the above statements, choose the correct answer from the options given below
Compound I is heated with Conc. HI to give a hydroxy compound A which is further heated with Zn dust to give compound B. Identify A and B.
Given Compounds
Animal starch is the other name of
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Boric acid is a weak acid
Reason R: Boric acid is not able to release \(H^+\) ion on its own. It receives \(OH^–\) ion from water and releases \(H^+\) ion.
In the light of the above statements, choose the most appropriate answer from the options given below.
Match List I with List II
 List I (polymer) List-II (Nature)
A.
 
A.
I.
Thermosetting polymer
B.
B.
II.
Fibers
C.
C.
III.
Elastomer
D.
D.
IV.Thermoplastic polymer
Choose the correct answer from the options given below:
The correct decreasing order of energy for the orbitals having, following set of quantum numbers:
(A) n = 3, l = 0, m = 0
(B) n = 4, l = 0, m = 0
(C) n = 3, l = 1, m = 0
(D) n = 3, l = 2, m = 1
The products obtained from a reaction of hydrogen peroxide and acidified potassium permanganate are
The major product in the given reaction is
Question Reaction
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. 
Assertion A : \(LiF\) is sparingly soluble in water.
Reason R : The ionic radius of \(Li^+\) ion is smallest among its group members, hence has least hydration enthalpy.
In the light of the above statements, choose the most appropriate answer from the options given below.
Among the following ores Bauxite, Siderite, Cuprite, Calamine, Haematite, Kaolinite, Malachite, Magnetite, Sphalerite, Limonite, Cryolite, the number of principal ores of iron is____.
Match List-I with List-II
List-I(Mixture) List-II(Purification Process)
(A) Chloroform & Aniline(I) Steam distillation
(B) Benzoic acid & Napthalene(II) Sublimation
(C) Water & Aniline(III) Distillation
(D) Napthalene & Sodium chloride(IV) Crystallisation
Choose the correct answer from the options given below: