List of top Questions asked in JEE Main

In an ideal gas at temperature $T$, the average force that a molecule applies on the walls of a closed container depends on $T$ as $T^q$. A good estimate for $q$ is :

The intermolecular interaction that is dependent on the inverse cube of distance between the molecules is

When does a gas deviate the most from its ideal behaviour ?

For plane electromagnetic waves propagating in the $z$ direction, which one of the following combination gives the correct possible direction for $\vec{E}$ and $\vec{B}$ field respectively ?

A train is moving on a straight track with speed $20\, ms^{-1}.$ It is blowing its whistle at the frequency of $1000\, Hz$. The percentage change in the frequency heard by a person standing near the track as the train passes him is close to (speed of sound $= 320\,ms^{-1}$)

A uniform solid cylindrical roller of mass '$m$' is being pulled on a horizontal surface with force $F$ parallel to the surface and applied at its centre. If the acceleration of the cylinder is '$a$' and it is rolling without slipping then the value of '$F$' is :

When current in a coil changes from $5 \,A$ to $2 \,A$ in $0.1\, s$, an average voltage of $50\, V$ is produced. The self - inductance of the coil is :

In the given circuit, charge $Q_2 $ on the $2 \mu F $ capacitor changes as $C$ is varied from $1 \mu F $ to $3 \mu F. $ $Q_2 $ as a function of $'C'$ is given properly by (figures are drawn schematically and are not to scale)

In the following figure is shown a system of four capacitors connected across a $10\, V$ battery. Charge that will flow from switch $S$ when it is closed is

A uniformly charged solid sphere of radius $R$ has potential $V _{0}\, 9$ measured with respect to $\infty$ ) on its surface. For this sphere the equipotential surfaces with potentials $\frac{3 V _{0}}{2}$, $\frac{5 V _{0}}{4}, \frac{3 V _{0}}{4}$ and $\frac{ V _{0}}{4}$ have radius $R _{1}, R _{2}, R _{3}$ and $R _{4}$ respectively. Then

In the electric network shown, when no current flows through the $4\, \Omega$ resistor in the arm $EB$, the potential difference between the points $A$ and $D$ will be :

When $5\,V$ potential difference is applied across a wire of length $0.1\,m$, the drift speed of electrons is $2.5\times10^{-4}$ $ms^{-1}$. If the electron density in the wire is $8\times10^{28}\, m^{-3}$ the resistivity of the material is close to

In Carius method of estimation of halogens $250\, mg$ of an organic compound gave $141\, mg$ of $AgBr$. The percentage of bromine in the compound is (atomic mass $Ag\, =\, 108, Br \,= \,80$)

Nitrogen and Oxygen are the main components in the atmosphere but these do not react to form oxides of nitrogen. The reaction between nitrogen and oxygen requires high temperature.

The ionic radii (in $?$) of $N^{3-},O^{2-} $ and $F^-$ respectively are

The number of geometric isomers that can exist for square planar $\left[ Pt ( Cl )( py )\left( NH _{3}\right)\right.$ $\left.\left( NH _{2} OH \right)\right]^{+}$ is $( py =$ pyridine $):$

Which artificial sweetener contains chlorine ?

Two Faraday of electricity is passed through a solution of $CuSO_4$. The mass of copper deposited at the cathode is (At. mass of $Cu\, = \,63.5\, u$)

Consider a spherical shell of radius $R$ at temperature $T$. The black body radiation inside it can be considered as an ideal gas of photons with internal energy per unit volume $u=\frac{U}{V} ? T^4$ and pressure $p=\frac{1}{3}\bigg(\frac{U}{V}\bigg)$ If the shell now undergoes an adiabatic expansion, the relation between $T$ and $R$ is

Consider an ideal gas confined in an isolated closed chamber. As the gas undergoes an adiabatic expansion, the average time of collision between molecules increases as $V^q$ , where $V$ is the volume of the gas. The value of $q$ is $\bigg(\gamma =\frac{C_p}{C_v}\bigg)$

A solid body of constant heat capacity $1 \, J/^{\circ}C$ is being heated by keeping it in contact with reservoirs in two ways (i) Sequentially keeping in contact with $2$ reservoirs such that each reservoir supplies same amount of heat. (ii) Sequentially keeping in contact with $8$ reservoirs such that each reservoir supplies same amount of heat. In both the cases, body is brought from initial temperature $100^{\circ}C$ to final temperature $200^{\circ}C$. Entropy change of the body in the two cases respectively, is

As an electron makes a transition from an excited state to the ground state of a hydrogen- like atom/ion

Two coaxial solenoids of different radii carry current $I$ in the same direction. Let $\vec{F}_1$ be the magnetic force on the inner solenoid due to the outer one and $\vec{F}_2$ be the magnetic force on the outer solenoid due to the inner one. Then,

A thin disc of radius $b\, = \,2a$ has a concentric hole of radius '$a$' in it (see figure). It carries uniform surface charge '$\sigma$' on it. If the electric field on its axis at height '$h$' $(h < < a)$ from its centre is given as '$Ch$' then value of '$C$' is :

A long cylindrical shell carries positive surface charge $\sigma$ in the upper half and negative surface charge $-\sigma$ in the lower half. The electric field lines around the cylinder will look like figure given in: (figures are schematic and not drawn to scale)