List of top Questions asked in JEE Main- 2024

Molality $(m)$ of $3 \, \text{M}$ aqueous solution of $\text{NaCl}$ is:
(Given: Density of solution $= 1.25 \, \text{g mL}^{-1}$, Molar mass in $\text{g mol}^{-1}$: $\text{Na} = 23, \, \text{Cl} = 35.5$)

The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency \( 'A' \times 10^{12} \, \text{hertz} \) and that has a radiant intensity in that direction of \( \frac{1}{'B'} \, \text{watt per steradian} \). 'A' and 'B' are respectively:

The quantity which changes with temperature:

Match List-I with the List-II

List-I (Hybridization)	List-II (Orientation in Space)
(A) sp3	(I) Trigonal bipyramidal
(B) dsp2	(II) Octahedral
(C) sp3d	(III) Tetrahedral
(D) sp3d2	(IV) Square planar

Choose the correct answer from the options given below:

Which among the following purification methods is based on the principle of “Solubility” in two different solvents?

Which of the following is least ionic ?

Given below are two statements :
Statement (I) : Dimethyl glyoxime forms a six-membered covalent chelate when treated with NiCl2 solution in presence of NH4OH.
Statement (II) : Prussian blue precipitate contains iron both in (+2) and (+3) oxidation states. In the light of the above statements,
choose the most appropriate answer from the options given below:

The compound that is white in color is

$\textbf{Match List I with List II}$
$\begin{array}{|c|c|c|} \hline \text{List I (Spectral Series for Hydrogen)} & \text{List II (Spectral Region/Higher Energy State)} \\ \hline \text{A. Lyman} & \text{I. Infrared region} \\ \text{B. Balmer} & \text{II. UV region} \\ \text{C. Paschen} & \text{III. Infrared region} \\ \text{D. Pfund} & \text{IV. Visible region} \\ \hline \end{array}$
$\text{Choose the correct answer from the options given below :-}$

Match List-I with List-II
\[ \begin{array}{|c|c|} \hline \text{List-I (Species)} & \text{List-II (Electronic distribution)} \\ \hline \text{(A) Cr}^{+2} & \text{(I) } 3d^8 \\ \text{(B) Mn}^{+} & \text{(II) } 3d^3 4s^1 \\ \text{(C) Ni}^{+2} & \text{(III) } 3d^4 \\ \text{(D) V}^{+} & \text{(IV) } 3d^5 4s^1 \\ \hline \end{array} \]

A small steel ball is dropped into a long cylinder containing glycerine. Which one of the following is the correct representation of the velocity time graph for the transit of the ball?

The electric field in an electromagnetic wave is moving in a free space given as vec \(E =E_ 0 \;sin(⍵t - kz)\) \(i\) The corresponding magnetic field will be:

A rigid wire consists of a semicircular portion of radius \( R \) and two straight sections. The wire is partially immersed in a perpendicular magnetic field \( \vec{B} = B_0 \hat{j} \) as shown in the figure.The magnetic force on the wire if it has a current \( i \) is:

The measured value of the length of a simple pendulum is 20 cm with 2 mm accuracy. The time for 50 oscillations was measured to be 40 seconds with 1 second resolution. From these measurements, the accuracy in the measurement of acceleration due to gravity is N%. The value of N is:

An alternating voltage \( V(t) = 220 \sin 100 \pi t \) volt is applied to a purely resistive load of 50 \( \Omega \). The time taken for the current to rise from half of the peak value to the peak value is:

The ratio of heat dissipated per second through the resistance 5 ohm and 10 ohm in the circuit given below is :

Correct Bernoulli's equation is (symbols have their usual meaning):

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:

If the distance between object and its two times magnified virtual image produced by a curved mirror is 15 cm, the focal length of the mirror must be :

A particle is executing simple harmonic motion along the \(x - axis\), with amplitude \(A\), about the origin. Then the ratio of Kinetic energy and total energy at \(x = \frac{A}{3}\) is

A satellite revolving around a planet in stationary orbit has time period 6 hours. The mass of planet is one-fourth the mass of earth. The radius orbit of planet is: (Given = Radius of geostationary orbit for earth is $4.2 \times 10^4$ km

A mixture of one mole of a monoatomic gas and one mole of a diatomic gas (rigid) are kept at room temperature (\(27^\circ \text{C}\)). The ratio of specific heat of gases at constant volume respectively is:

A metal wire of uniform mass density having length L and mass M is bent to form a semicircular arc and a particle of mass m is placed at the centre of the arc. The gravitational force on the particle by the wire is:

A Zener diode of breakdown voltage 10V is used as a voltage regulator as shown in the figure. The current through the Zener diode is

The temperature of a gas is \(-78^\circ\text{C}\) and the average translational kinetic energy of its molecules is \( K \). The temperature at which the average translational kinetic energy of the molecules of the same gas becomes \( 2K \) is: