List of top Questions asked in JEE Main

Noradrenaline is a /an
The correct order of the oxidation states of nitrogen in $NO, N_2O, NO_2$ and $N_2 O_3$ is :
The increasing order of nucleophilicity of the following nucleophiles is : (a) ${CH_3CO^{\ominus}_2}$ (b) ${H_2O} $ (c) ${CH_3SO^{\ominus}_3}$ (d) ${O^{\ominus}H}$
One mole of an ideal gas passes through a process where pressure and volume obey the relation $P =P_{o} \left[1- \frac{1}{2} \left(\frac{V_{0}}{V}\right)^{2}\right] $ .Here $P_o$ and $V_o$ are constants. Calculate the change in the temperature of the gas if its volume changes from $V_o$ to $2 V_o$ .
When $M_1$ gram of ice at $-10^{\circ}C$ (specific heat = $0.5 \; cal \; g^{-1 \circ } C^{-1}$) is added to $M_2$ gram of water at $50^{\circ}C$, finally no ice is left and the water is at $0^{\circ}C$. The value of latent heat of ice, in cal $g^{-1}$ is:
The correct statement among the following is
A test particle is moving in a circular orbit in the gravitational field produced by a mass density \(\rho(r) = \frac{K}{r^2}\). Identify the correct relation between the radius \(R\) of the particle's orbit and it's period \(T\) :
A magnetic compass needle oscillates $30$ times per minute at a place where the dip is $45^{\circ}$, and $40$ times per minute where the dip is $30^{\circ}$. If $B_1$ and $B_2$ are respectively the total magnetic field due to the earth at the two places, then the ratio $B_1/B_2$ is best given by :
A solid sphere of mass $'M'$ and radius $'a'$ is surrounded by a uniform concentric spherical shell of thickness $2a$ and mass $2M$. The gravitational field at distance $'3a'$ from the centre will be :
A particle having the same charge as of electron moves in a circular path of radius $0.5\, cm$ under the influence of a magnetic field of $0.5\, T$. If an electric field of $100\, V/m$ makes it to move in a straight path, then the mass of the particle is (Given charge of electron = $1.6 \times 10^{-19} C)$
Diborane ${(B2H6)}$ reacts independently with ${O_2}$ and ${H2O}$ to produce, respectively
The major product formed in the following reaction is:
Correct statements among $a$ to $d$ regarding silicones are : (a) They are polymers with hydrophobic character (b) They are biocompatible. (c) In general, they have high thermal stability and low dielectric strenth. (d) Usually, they are resistant to oxidation and used as greases.
Among the following molecules / ions, $C^{2-}_{2}, N^{2-}_{2}, O^{2-}_{2}, O_{2}$ which one is diamagnetic and has the shortest bond length?
The amphoteric hydroxide is :
The percentage composition of carbon by mole in methane is :
Assume that each born child is equally likely to be a boy or a girl. If two families have two children each, then the conditional probability that all children are girls given that at least two are girls is :
The structure of Nylon-6 is :
In a simple pendulum experiment for determination of acceleration due to gravity (g), time taken for $20$ oscillations is measured by using a watch of $1$ second least count. The mean value of time taken comes out to be $30\, s$. The length of pendulum is measured by using a meter scale of least count $1\, mm$ and the value obtained is $55.0\, cm$. The percentage error in the determination of $g$ is close to :
Consider the $bcc$ unit cells of the solids $1$ and $2$ with the position of atoms as shown below. The radius of atom $B$ is twice that of atom $A$. The unit cell edge length is $50\%$ more in solid $2$ than in $1$. What is the approximate packing efficiency in solid $2$ ?
${K_2HgI_4}$ is $40\%$ ionised in aqueous solution. The value of its van't Hoff factor (i) is :
A uniform cylindrical rod of length $L$ and radius $r$, is made from a material whose Young's modulus of Elasticity equals $Y$. When this rod is heated by temperature $T$ and simultaneously subjected to a net longitudinal compressional force $F$, its length remains unchanged. The coefficient of volume expansion, of the material of the rod, is (nearly) equals to :
Two point charges $q_1( \sqrt{10} \mu C)$ and $q_2(-25 \; \mu C)$ are placed on the x-axis at $x = 1 m$ and $x = 4 m$ respectively. The electric field (in V/m) at a point $y = 3 m$ on y-axis is, $\left[\text{take} \frac{1}{4\pi\varepsilon_{0}} = 9\times10^{9} Nm^{2} C^{-2}\right] $
If dichloromethane (DCM) and water ${(H_2O)}$ are used for differential extraction, which one of the following statements is correct ?
If speed $(V)$, acceleration $(A)$ and force $(F)$ are considered as fundamental units, the dimension of Young's modulus will be :