List of top Questions asked in JEE Main

A process has \(\Delta\)H = 200 J mol\(^{-1}\) and \(\Delta\)S = 40 JK\(^{-1}\) mol\(^{-1}\). Out of the values given below, choose the minimum temperature above which the process will be spontaneous :

The major product 'X' formed in the following reaction is :

(Reactant: a cyclohexenone carrying a \(-\mathrm{CH_2COOCH_3}\) group on the carbon next to C=O; reagent: NaBH\(_4\), MeOH.)

The major product of the following reaction is

The decreasing order of ease of alkaline hydrolysis for the following esters in

(I) ethyl benzoate; (II) ethyl 4-chlorobenzoate; (III) ethyl 4-nitrobenzoate; (IV) ethyl 4-methoxybenzoate

The values of K\(_p\)/K\(_c\) for the following reactions at 300 K are, respectively : (At 300 K, RT = 24.62 dm\(^3\) atm mol\(^{-1}\))
\(\mathrm{N_2(g) + O_2(g) \rightleftharpoons 2\,NO(g)}\)
\(\mathrm{N_2O_4(g) \rightleftharpoons 2\,NO(g)}\)
\(\mathrm{N_2(g) + 3H_2(g) \rightleftharpoons 2\,NH_3(g)}\)

The major product of the following reaction is :

(Reactant: \(\mathrm{3\text{-}CH_3O\text{-}C_6H_4\text{-}CH_2CH_2CH(CH_3)CH_2Cl}\); reagents: (i) AlCl\(_3\) (anhyd.), (ii) H\(_2\)O.)

The major product formed in the reaction given below will be :

(Reactant: a hydrindane (cyclohexane fused to cyclopentane) carrying a \(-\mathrm{CH_2NH_2}\) group on the five-membered ring; reagent: NaNO\(_2\), aq. HCl, 0-5\(^\circ\)C.)

The electronegativity of aluminium is similar to :

The correct structure of product 'P' in the following reactions is :
\(\mathrm{Asn - Ser + (CH_3CO)_2O\ (excess)\ \xrightarrow{NEt_3}\ P}\)

The type of hybridisation and number of lone pair (s) of electrons of Xe in XeOF\(_4\), respectively, are:

Which of the graphs shown below does not represent the relationship between incident light and the electron ejected from metal surface ?

The total number of isomers for a square planar complex [M(F)(Cl)(SCN)(NO\(_2\))] is

A train moves towards a stationary observer with speed 34 m/s. The train sounds a whistle and its frequency registered by the observer is \(f_1\). If the speed of the train is reduced to 17 m/s, the frequency registered is \(f_2\). If speed of sound is 340 m/s, then the ratio \(f_1/f_2\) is -

Using a nuclear counter the count rate of emitted particles from a radioactive source is measured. At t = 0 it was 1600 counts per second and t = 8 seconds it was 100 counts per second. The count rate observed, as counts per second, at t = 6 seconds is close to -

The increasing order of the pKa values of the following compounds is :

(A) phenol; (B) 4-nitrophenol; (C) 3-nitrophenol; (D) 4-methoxyphenol

A TV transmission tower has a height of 140 m and the height of the receiving antenna is 40 m. What is the maximum distance upto which signals can be broadcasted from this tower is LOS (Line of Sight) mode ? (Given : radius of earth = \(6.4 \times 10^{6}\) m).

A mixture of 100 m mol of Ca(OH)\(_2\) and 2 g of sodium sulphate was dissolved in water and the volume was made up to 100 mL. The mass of calcium sulphate formed and the concentration of OH\(^-\) in resulting solution, respectively, are : (Molar mass of Ca (OH)\(_2\), Na\(_2\)SO\(_4\) and CaSO\(_4\) are 74, 143 and 136 g mol\(^{-1}\), respectively; K\(_{sp}\) of Ca(OH)\(_2\) is \(5.5 \times 10^{-6}\) )

Which dicarboxylic acid in presence of a dehydrating agent is least reactive to give an anhydride?

If the magnetic field of a plane electromagnetic wave is given by (the speed of light = \(3\times10^{8}\) B = \(100\times10^{-6}\) sin
\(\left[2\pi\times2\times10^{15}\left(t-\frac{x}{c}\right)\right]\)
then the maximum electric field associated with it is -

In an electron microscope, the resolution that can be achieved is of the order of the wavelength of electrons used. To resolve a width of \(7.5\times10^{-12}\) m, the minimum electron energy required is close to -

To get output 1 at R, for the given logic gate circuit the input values must be

A block of mass m is kept on a platform which starts from rest with constant acceleration g/2 upward, as shown in figure. Work done by normal reaction on block in time \(t\) is -

A solid metal cube of edge length 2 cm is moving in a positive y-direction at a constant speed of 6 m/s. There is a uniform magnetic field of 0.1 T in the positive z-direction. The potential difference between the two faces of the cube perpendicular to the x-axis, is -

A satellite is moving with a constant speed v in circular orbit around the earth. An object of mass 'm' is ejected from the satellite such that it just escapes from the gravitational pull of the earth. At the time of ejection, the kinetic energy of the object is -

Let A be a point on the line \(\vec{r} = (1-3\mu)\hat{i} + (\mu-1)\hat{j} + (2+5\mu)\hat{k}\) and B(3, 2, 6) be a point in the space. Then the value of \(\mu\) for which the vector \(\overrightarrow{AB}\) is parallel to the plane \(x - 4y + 3z = 1\) is -