List of top Questions asked in JEE Main

When \( \text{MnO}_2 \) and \( \text{H}_2\text{SO}_4 \) is added to a salt (A), the greenish yellow gas liberated as salt (A) is:

Find out the major product formed from the following reaction.\([ \text{Me: } -\text{CH}_3 ]\)

The equilibrium constant for the reaction
\( \text{SO}_3 \, (g) \rightleftharpoons \text{SO}_2 \, (g) + \frac{1}{2} \text{O}_2 \, (g) \)
is \( K_C = 4.9 \times 10^{-2} \). The value of \( K_C \) for the reaction given below is
\( 2 \text{SO}_2 \, (g) + \text{O}_2 \, (g) \rightleftharpoons 2 \text{SO}_3 \, (g) \) is

Mercury is filled in a tube of radius \(2 \, \text{cm}\) up to a height of \(30 \, \text{cm}\). The force exerted by mercury on the bottom of the tube is ___N.
(Given, atmospheric pressure = \(10^5 \, \text{N/m}^2\), density of mercury = \(1.36 \times 10^4 \, \text{kg/m}^3\), \(g = 10 \, \text{m/s}^2\), \(\pi = \frac{22}{7}\))

Two parallel long current carrying wire separated by a distance $2r$ are shown in the figure. The ratio of magnetic field at $A$ to the magnetic field produced at $C$ is $\frac{x}{7}$. The value of $x$ is ___.

Two wires A and B are made up of the same material and have the same mass. Wire A has radius \(2.0 \, \text{mm}\) and wire B has radius \(4.0 \, \text{mm}\). The resistance of wire B is \(2 \, \Omega\). The resistance of wire A is _____ \( \Omega \).

A rod of length 60 cm rotates with a uniform angular velocity \(20 \, \text{rad} \, \text{s}^{-1}\) about its perpendicular bisector, in a uniform magnetic field \(0.5 \, \text{T}\). The direction of the magnetic field is parallel to the axis of rotation. The potential difference between the two ends of the rod is _____ V.

A light ray is incident on a glass slab of thickness \(4\sqrt{3}\) cm and refractive index \(\sqrt{2}\). The angle of incidence is equal to the critical angle for the glass slab with air. The lateral displacement of the ray after passing through the glass slab is _____ cm.
(Given \(\sin 15^\circ = 0.25\))

In a system, two particles of masses \( m_1 = 3 \, \text{kg} \) and \( m_2 = 2 \, \text{kg} \) are placed at a certain distance from each other. The particle of mass \( m_1 \) is moved towards the center of mass of the system through a distance \( 2 \, \text{cm} \). In order to keep the center of mass of the system at the original position, the particle of mass \( m_2 \) should move towards the center of mass by the distance ______ \( \, \text{cm} \).

A bus moving along a straight highway with speed of 72 km/h is brought to halt within 4s after applying the brakes. The distance travelled by the bus during this time (Assume the retardation is uniform) is _______m.

The displacement of a particle executing SHM is given by \( x = 10 \sin\left(\omega t + \frac{\pi}{3}\right) \, \text{m} \). The time period of motion is \( 3.14 \, \text{s} \). The velocity of the particle at \( t = 0 \) is ______ m/s.

A 90 kg body placed at \( 2R \) distance from the surface of the earth experiences gravitational pull of:
(\( R \) = Radius of Earth, \( g = 10 \, \text{ms}^{-2} \)).

Applying the principle of homogeneity of dimensions, determine which one is correct. Where \( T \) is the time period, \( G \) is the gravitational constant, \( M \) is the mass, and \( r \) is the radius of the orbit.

A charge q is placed at the center of one of the surface of a cube. The flux linked with the cube is :-

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):

According to Bohr's theory, the moment of momentum of an electron revolving in the 4^th orbit of a hydrogen atom is:

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Number of photons increases with increase in frequency of light.
Reason (R): Maximum kinetic energy of emitted electrons increases with the frequency of incident radiation.
In the light of the above statements, choose the most appropriate answer from the options given below:

In simple harmonic motion, the total mechanical energy of the given system is \( E \). If the mass of the oscillating particle \( P \) is doubled, then the new energy of the system for the same amplitude is:

A 2 kg brick begins to slide over a surface which is inclined at an angle of \( 45^\circ \) with respect to the horizontal axis. The coefficient of static friction between their surfaces is:

An electric bulb rated 50 W – 200 V is connected across a 100 V supply. The power dissipation of the bulb is :

A body of m kg slides from rest along the curve of vertical circle from point A to B in friction less path. The velocity of the body at B is :

(Given, \( R = 14 \, \text{m}, \, g = 10 \, \text{m/s}^2 \, \text{and} \, \sqrt{2} = 1.4 \))

Given below are two statements :
Statement I : The contact angle between a solid and a liquid is a property of the material of the solid and liquid as well.
Statement II : The rise of a liquid in a capillary tube does not depend on the inner radius of the tube.
In the light of the above statements, choose the correct answer from the options given below :

If 5 moles of an ideal gas expands from \( 10 \, L \) to a volume of \( 100 \, L \) at \( 300 \, K \) under isothermal and reversible conditions, then work, \( w \), is \( -x \, J \). The value of \( x \) is ______.
(Given \( R = 8.314 \, \text{J K}^{-1} \text{mol}^{-1} \))

From the vitamins \( A, \, B_1, \, B_6, \, B_{12}, \, C, \, D, \, E, \, \text{and} \, K \), the number of vitamins that can be stored in our body is ______.