List of top Questions asked in JEE Main

In Dumas' method for estimation of nitrogen 1 g of an organic compound gave 150 mL of nitrogen collected at 300 K temperature and 900 mm Hg pressure. The percentage composition of nitrogen in the compound is _______ % (nearest integer). (Aqueous tension at $300 \mathrm{~K}=15 \mathrm{~mm} \mathrm{Hg}$ )

40 mL of a mixture of CH$_3$COOH and HCl (aqueous solution) is titrated against 0.1 M NaOH solution conductometrically. Which of the following statement is correct?

Compounds that should not be used as primary standards in titrimetric analysis are : A. Na$ _2 $Cr$ _2 $O$ _7 $ B. Oxalic acid C. NaOH D. FeSO$ _4 $.6H$ _2 $O E. Sodium tetraborate Choose the most appropriate answer from the options given below :

In Dumas' method for estimation of nitrogen 0.4 g of an organic compound gave 60 mL of nitrogen collected at 300 K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in the compound is (Given : Aqueous tension at 300 K = 15 mm Hg)

A particle is subjected to simple harmonic motions as: $ x_1 = \sqrt{7} \sin 5t \, \text{cm} $ $ x_2 = 2 \sqrt{7} \sin \left( 5t + \frac{\pi}{3} \right) \, \text{cm} $ where $ x $ is displacement and $ t $ is time in seconds. The maximum acceleration of the particle is $ x \times 10^{-2} \, \text{m/s}^2 $. The value of $ x $ is:

For a particular ideal gas, which of the following graphs represents the variation of mean squared velocity of the gas molecules with temperature?

The alkane from below having two secondary hydrogens is:

An alternating current is given by \[ I = I_A \sin \omega t + I_B \cos \omega t. \] The r.m.s. current will be:

Which of the following ions is the strongest oxidizing agent? (Atomic Number of Ce = 58, Eu = 63, Tb = 65, Lu = 71)

Identify correct statements: (A) Primary amines do not give diazonium salts when treated with ${NaNO}_2$ in acidic condition.
(B) Aliphatic and aromatic primary amines on heating with ${CHCl}_3$ and ethanolic ${KOH}$ form carbylamines.
(C) Secondary and tertiary amines also give carbylamine test.
(D) Benzenesulfonyl chloride is known as Hinsberg’s reagent.
(E) Tertiary amines react with benzenesulfonyl chloride very easily.
Choose the correct answer from the options given below:

Mean free path for an ideal gas is observed to be 20 μm while the average speed of molecules of gas is observed to be 600 m/s, then the frequency of collision is near?

The amplitude and phase of the wave when two travelling waves given as $ y_1(x, t) = 4 \sin(\omega t - kx) $ and $ y_2(x, t) = 2 \sin\left(\omega t - kx + \frac{2\pi}{3}\right) $ are superimposed.

Among the statements: (S1): The set $ \{ z \in \mathbb{C} - \{-i\} : |z| = 1 \text{ and } \frac{z - i}{z + i} \text{ is purely real} \} $ contains exactly two elements.
(S2): The set $ \{ z \in \mathbb{C} - \{-1\} : |z| = 1 \text{ and } \frac{z - 1}{z + 1} \text{ is purely imaginary} \} $ contains infinitely many elements. Then, which of the following is correct?

If $ z_1, z_2, z_3 \in \mathbb{C} $ are the vertices of an equilateral triangle, whose centroid is $ z_0 $, then $ \sum_{k=1}^{3} (z_k - z_0)^2 $ is equal to

The helium and argon are put in the flask at the same room temperature (300 K). The ratio of average kinetic energies (per molecule) of helium and argon is : (Give : Molar mass of helium = 4 g/mol, Molar mass of argon = 40 g/ mol )

Let $ A = \{1, 2, 3, 4\} $ and $ B = \{1, 4, 9, 16\} $. Then the number of many-one functions $ f: A \to B $ such that $ 1 \in f(A) $ is equal to:

A plane electromagnetic wave of frequency 20 MHz travels in free space along the +x direction. At a particular point in space and time, the electric field vector of the wave is $ E_y = 9.3 \, \text{V/m} $. Then, the magnetic field vector of the wave at that point is:

Match List-I with List-II:

Choose the correct answer from the options given below:

The domain of the function \[ f(x) = \frac{1}{\sqrt{10 + 3x - x^2}} + \frac{1}{\sqrt{x + |x|}} \] is $ (a, b) $. Then $ (1 + a^2) + b^2 $ is:

Consider a n-type semiconductor in which $ n_e $ and $ n_h $ are the number of electrons and holes, respectively.

The standard cell potential (E$^\circ_{cell}$) of a fuel cell based on the oxidation of methanol in air that has been used to power a television relay station is measured as 1.21 V. The standard half cell reduction potential for O$ _2 $/H$ _2 $O (E$^\circ_{O_2/H_2O}$) is 1.229 V. Choose the correct statement:

If the domain of the function $ f(x) = \dfrac{1}{\sqrt{10 + 3x - x^2}} + \dfrac{1}{\sqrt{x + |x|}} $ is $ (a, b) $, then $(1 + a)^2 + b^2$ is equal to:

Given below are two statements, one labeled as Assertion (A) and the other as Reason (R).
Assertion (A): In Young’s double slit experiment, the fringes produced by red light are closer compared to those produced by blue light.
Reason (R): The fringe width is directly proportional to the wavelength of light.
In the light of the above statements, choose the correct answer from the options given below:

Two long parallel wires X and Y, separated by a distance of 6 cm, carry currents of 5 A and 4 A, respectively, in opposite directions as shown in the figure. Magnitude of the resultant magnetic field at point P at a distance of 4 cm from wire Y is $ 3 \times 10^{-5} $ T. The value of $ x $, which represents the distance of point P from wire X, is$ \_\_\_\_\_$ cm. (Take permeability of free space as $ \mu_0 = 4\pi \times 10^{-7} $ SI units.)

Consider an elementary reaction: \[ A(g) + B(g) \rightarrow C(g) + D(g) \] If the volume of the reaction mixture is suddenly reduced to $ \frac{1}{3} $ of its initial volume, the reaction rate will become $ x $ times of the original reaction rate. The value of $ x $ is: