List of top Questions asked in JEE Main

Bond dissociation energy of $XY,X_2$, and $Y_2$ (all diatomic molecules) are in the ratio of $1:1:0.5$ and $\mathrm{\Delta }{H}_f$ of $XY$ is $-100kJ{mol}^{-1}$. The bond dissociation energy of $X_2$ is $100x.$ The value of $x$ is

Which graph correctly represents the photo current (i) vs stopping potential (Vs) for the same frequency but different intensity? $(here, I_1 › I_2)$

Two persons are pulling a rope towards themselves with a force of 200 N each. If the Young's modulus is 2 x 10¹¹ N/m² and area of cross-section is 2 cm² for the rope, the elongation in the rope is ____.
(distance between the persons holding the ropes is 2 m.)

The angle of polarization of glass is 58° and that for water is 53°. The angle of polarization for glass in water is

if  $∫_{-1}^1 \frac{cos \, \alpha x}{1+3^x} dx = \frac2{\pi} $ then $\alpha$ is

In a clock, second hand and minute hand are of 75 cm and 60 cm respectively. After 30 minutes, ratio of distance travelled by the tip of second hand to that of minute hand is x. Find x.

A cubical arrangement of 12 resistors each having resistance R is shown. Find I.

The PV curve shown in the diagram consists of two isothermal and two adiabatic curves. Then:

A = {2,4,6,8}, B = {3,7,6,9}. R: A × B → A × B such that (a₁, b₁) R (a₂, b₂) ⇔ a₁ + a₂ = b₁ + b₂ where (a₁, b₁) ∈ A, (a₂, b₂) ∈ B. Find the number of elements in the relation.2)= 4, then find (a² + b² + c²).

If A is 3 x 3 matrix, det(3adj (2 adj A)) = 2^-13. 3^-10 and det(3adj (2A)) = 2^-m. 3^-n, then find 2m + 2n.d by 21?

A, B and C are given as
A = αî + 4j + 5k
B = 2î + 5j + 6k
C=A+B
|C| = | A - B |
Find the value of α and |C|² is:

A circle passes through (0, 0) and (1, 0) and touches the circle x² + y² = 9. Then the locus of the centre of the circle is:

Tetrahedral dice having outcomes (1, 2, 3, 4) has 3 outcomes a, b, c (which are visible). Probability that ax² + bx + c = 0 has real roots is m/n (m, n are coprime), then m + n =?

Which of the following statements is incorrect?

Consider the reaction between PbS and HNO₃.
PbS + HNO₃ →
Which of the following is not formed.

S-I: Sulphur exists as S8 while oxygen exists as O2.
S-II: In oxygen, pπ-pπ bonding occurs while it is not effective in sulphur.

Which among the following have a single unpaired electron?
N₂, 0₂, CN^-, O₂^-, C₂^2- , N^2-

Which of the following is colorless?

Consider the following compound.

Correct order of their basicity is:

Arrange the following in increasing order of acidity.

Which of the following orbitals has the highest energy?

Number of ambidentate nucleophiles among the following is:
CN^-, SCN^- NO₂^-, CH₃COO^-, C₂0₄^2-, NH₂^-, SO₄^2-

Equal volume of 1 M HCI and 1 M H2SO4 neutralized by dil. NaOH and heat released is x and y kcal respectively, then which is correct?

Chemical formula of compound present in tooth enamel?

Consider the following electronic configuration:
Cu²⁺ = [Ar] 3d⁴4s⁰
Cu⁺ = [Ar] 3d¹⁰4s⁰
Which option is correct?