List of top Questions asked in JEE Main

Given below are two statements:
Statement-I: The orbitals having same energy are called as degenerate orbitals.
Statement-II: In hydrogen atom, 3p and 3d orbitals are not degenerate orbitals.
In the light of the above statements, choose the most appropriate answer from the options given

In which of the following compound central atom has +4 oxidation state?

Identify A and B in the given chemical reaction sequence : -

Choose the correct statements from the following:
A Ethane-1,2-diamine is a chelating ligand.
B Metallic aluminium is produced by electrolysis of aluminium oxide in presence of cryolite.
C Cyanide ion is used as a ligand for leaching of silver.
D Phosphine acts as a ligand in Wilkinson catalyst.
E The stability constants of \( \text{Ca}^{2+} \) and \( \text{Mg}^{2+} \) are similar to EDTA complexes.

Given below are two statements:
One is labelled as Assertion A and the other is labelled as Reason R: 
Assertion A: \(pK_a\)​ value of phenol is 10.0 while that of ethanol is 15.9. 
Reason R: Ethanol is stronger acid than phenol. 
In the light of the above statements, choose the correct answer from the options given below:

The correct statements among the following, for a "chromatography" purification method is:

The electric field of an electromagnetic wave in free space is represented as \( \vec{E} = E_0 \cos(\omega t - kz) \hat{i} \). The corresponding magnetic induction vector will be:

The binding energy of a certain nucleus is \(18 \times 10^8 \, \text{J}\). How much is the difference between the total mass of all the nucleons and the nuclear mass of the given nucleus?

Arrange the following in the ascending order of wavelength:
(A) Gamma rays (\( \lambda_1 \))
(B) X-ray (\( \lambda_2 \))
(C) Infrared waves (\( \lambda_3 \))
(D) Microwaves (\( \lambda_4 \))
Choose the most appropriate answer from the options given below:

Conductivity of a photodiode starts changing only if the wavelength of incident light is less than 660 nm. The band gap of the photodiode is found to be \[\frac{X}{8} \, \text{eV}.\]The value of $X$ is:\text{(Given, $h = 6.6 \times 10^{-34} \, \text{Js}$, $e = 1.6 \times 10^{-19} \, \text{C}$)}

A sample of gas at temperature \( T \) is adiabatically expanded to double its volume. Adiabatic constant for the gas is \( \gamma = \frac{3}{2} \). The work done by the gas in the process is (\( \mu = 1 \) mole):

The voltage applied across the resistance R is 200+5 and current in resistance is 20+0.2 then find % error in resistance.

In the given circuit, find electric current drawn from battery :

Draw truth table of given gate circuit.

Ice at temperature –10°C is converted to steam at 100°C, the curve plotted between temperature (T) and time (t) when it is being heated by constant power source is

Four particles A, B, C, D of mass $\frac{m}{2}$, $m$, $2m$, $4m$ have the same momentum, respectively. The particle with maximum kinetic energy is:

In a plane EM wave, the electric field oscillates sinusoidally at a frequency of \( 5 \times 10^{10} \, \text{Hz} \) and an amplitude of \( 50 \, \text{Vm}^{-1} \). The total average energy density of the electromagnetic field of the wave is: \([ \text{Use } \epsilon_0 = 8.85 \times 10^{-12} \, \text{C}^2 / \text{Nm}^2 ]\)

Match List - I with List - II.

List - I(Number)	List - II(Significant figure)
(A) 1001	(I) 3
(B) 010.1	(II) 4
(C) 100.100	(III) 5
(D) 0.0010010	(IV) 6

Choose the correct answer from the options given below :

On passing a gas, ‘X’, through Nessler’s reagent, a brown precipitate is obtained. The gas ‘X’ is

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Cis form of alkene is found to be more polar than the trans form
Reason (R): Dipole moment of trans isomer of 2-butene is zero. In the light of the above statements.
Choose the correct answer from the options given below :

Given below are two statements:
Statement I:

IUPAC name of Compound A is 4-chloro-1, 3-dinitrobenzene.
Statement II:

IUPAC name of Compound B is 4-ethyl-2-methylaniline.
In the light of the above statements, choose the most appropriate answer from the options given below:

Let \( \alpha, \beta \) be the roots of the equation \( x^2 - x + 2 = 0 \) with \( \text{Im}(\alpha) > \text{Im}(\beta) \). Then \( \alpha^6 + \alpha^4 + \beta^4 - 5 \alpha^2 \) is equal to

Which one of the following will show geometrical isomerism?

In the given circuit if the power rating of Zener diode is 10 mW, the value of series resistance Rs to regulate the input unregulated supply is :

Let the positive integers be written in the form :

If the $k^\text{th}$ row contains exactly $k$ numbers for every natural number $k$, then the row in which the number $5310$ will be, is _____