List of top Questions asked in JEE Main

The correct order of basic nature on aqueous solution for the bases $ \text{NH}_3 $, $ \text{NH}_2 $, $ \text{CH}_3 \text{NH}_2 $, $ \text{CH}_3 \text{CH}_2 \text{NH}_2 $, $ (\text{CH}_3 \text{CH}_2)_2 \text{NH} $ is:

Given below are two statements:
Statement I: Vanillin will react with NaOH and also with Tollen’s reagent.

Statement II: Vanillin will undergo self-aldol condensation very easily.

In the light of the above statements, choose the most appropriate answer from the options given below:

Among SO₃, NF₃, NH₃, XeF₂, CIF$_3$, and SF₆, the hybridization of the molecule with non-zero dipole moment and one or more lone-pairs of electrons on the central atom is:

A solution is made by mixing one mole of volatile liquid A with 3 moles of volatile liquid B. The vapor pressure of pure A is 200 mm Hg and that of the solution is 500 mm Hg. The vapor pressure of pure B and the least volatile component of the solution, respectively, are:

Two vessels A and B are connected via stopcock. Vessel A is filled with a gas at a certain pressure. The entire assembly is immersed in water and allowed to come to thermal equilibrium with water. After opening the stopcock the gas from vessel A expands into vessel B and no change in temperature is observed in the thermometer. Which of the following statement is true?

Which of the following graph correctly represents the plots of $K_H$ at 1 bar gases in water versus temperature?

An optically active alkyl halide C$_4$H$_9$Br [A] reacts with hot KOH dissolved in ethanol and forms alkene [B] as major product which reacts with bromine to give dibromide [C]. The compound [C] is converted into a gas [D] upon reacting with alcoholic NaNH$_2$. During hydration 18 gram of water is added to 1 mole of gas [D] on warming with mercuric sulphate and dilute acid at 333 K to form compound [E]. The IUPAC name of compound [E] is :

The property/properties that show irregularity in the first four elements of group-17 are:

Designate whether each of the following compounds is aromatic or not aromatic.

A person travelling on a straight line moves with a uniform velocity $ v_1 $ for a distance $ x $ and with a uniform velocity $ v_2 $ for the next $ \frac{3x}{2} $ distance. The average velocity in this motion is $ \frac{50}{7} \, \text{m/s} $. If $ v_1 $ is 5 m/s, then $ v_2 $ is ___ m/s.

$\gamma_A$ is the specific heat ratio of monoatomic gas A having 3 translational degrees of freedom. $\gamma_B$ is the specific heat ratio of polyatomic gas B having 3 translational, 3 rotational degrees of freedom and 1 vibrational mode. If \[ \frac{\gamma_A}{\gamma_B} = \left( 1 + \frac{1}{n} \right) \] then the value of $ n $ is ___.

A monochromatic light is incident on a metallic plate having work function $ \phi $. An electron, emitted normally to the plate from a point A with maximum kinetic energy, enters a constant magnetic field, perpendicular to the initial velocity of the electron. The electron passes through a curve and hits back the plate at a point B. The distance between A and B is:

There are ‘n’ number of identical electric bulbs, each is designed to draw a power $ p $ independently from the mains supply. They are now joined in series across the main supply. The total power drawn by the combination is:

A spherical surface separates two media of refractive indices $ n_1 = 1 $ and $ n_2 = 1.5 $ as shown in the figure. Distance of the image of an object $ O $, if $ C $ is the center of curvature of the spherical surface and $ R $ is the radius of curvature, is:

Moment of inertia of a rod of mass $ M $ and length $ L $ about an axis passing through its center and normal to its length is $ \alpha $. Now the rod is cut into two equal parts and these parts are joined symmetrically to form a cross shape. Moment of inertia of cross about an axis passing through its center and normal to the plane containing cross is:

Considering Bohr’s atomic model for hydrogen atom :
(A) the energy of H atom in ground state is same as energy of He+ ion in its first excited state.
(B) the energy of H atom in ground state is same as that for Li++ ion in its second excited state.
(C) the energy of H atom in its ground state is same as that of He+ ion for its ground state.
(D) the energy of He+ ion in its first excited state is same as that for Li++ ion in its ground state.

Let the three sides of a triangle ABC be given by the vectors $$ 2\hat{i} - \hat{j} + \hat{k}, \quad \hat{i} - 3\hat{j} - 5\hat{k}, \quad \text{and} \quad 3\hat{i} - 4\hat{j} - 4\hat{k}. $$ Let G be the centroid of the triangle ABC. Then $$ 6 \left( |\vec{AG}|^2 + |\vec{BG}|^2 + |\vec{CG}|^2 \right) \text{ is equal to}$$ _______

A square Lamina OABC of length 10 cm is pivoted at $ O $. Forces act at Lamina as shown in figure. If Lamina remains stationary, then the magnitude of $ F $ is:

In an adiabatic process, which of the following statements is true?

A card from a pack of 52 cards is lost. From the remaining 51 cards, n cards are drawn and are found to be spades. If the probability of the lost card to be a spade is $\frac{11}{50}, \text{ then } n \text{ is equal to}$ _______

If $ \alpha $ is a root of the equation $ x^2 + x + 1 = 0 $ and $$ \sum_{k=1}^{n} \left( \alpha^k + \frac{1}{\alpha^k} \right)^2 = 20$$, then n is equal to _______

A zener diode with 5V zener voltage is used to regulate an unregulated dc voltage input of 25V. For a 400 $ \Omega $ resistor connected in series, the zener current is found to be 4 times load current. The load current $ I_L $ and load resistance $ R_L $ are:

Let the mean and the standard deviation of the observations $ 2, 3, 4, 5, 7, a, b $ be $ 4 $ and $ \sqrt{2} $ respectively. Then the mean deviation about the mode of these observations is:

Let A be the point of intersection of the lines $$ L_1 : \frac{x - 7}{1} = \frac{y - 5}{0} = \frac{z - 3}{-1} \quad \text{and} \quad L_2 : \frac{x - 1}{3} = \frac{y + 3}{4} = \frac{z + 7}{5}$$ Let B and C be the points on the lines $ L_1 $ and $ L_2 $, respectively, such that $ AB - AC = \sqrt{15} $. Then the square of the area of the triangle ABC is:

The relationship between the magnetic susceptibility $ \chi $ and the magnetic permeability $ \mu $ is given by:
$ \mu_0 $ is the permeability of free space and $ \mu_r $ is relative permeability.