List of top Questions asked in JEE Main- 2018

The decreasing order of bond angles in $BF_{3} , NH_{3} , PF_{3}$ and $I_{3}{^{-}}$ is

For which of the following reactions, $\Delta H$ is equal to $\Delta U$ ?

The major product obtained in the following reaction is
 

Lithium aluminium hydride reacts with silicon tetrachloride to form :

The oxidation states of $Cr$ in $ [Cr(H_2O)_6]Cl_3, [Cr(C_6H_6)_2]$, and $K_2[Cr(CN)_2(O)_2(O_2)(NH_3)]$ respectively are :

The most polar compound among the following is :

For $Na^{+}, Mg^{2+}, F^{-}$ and $O^{2-}$; the correct order of increasing ionic radii is :

When an electric current is passed through acidified water, $112\, mL$ of hydrogen gas at N.T.P. was collected at the cathode in $965$ seconds. The current passed, in ampere, is :

For a first order reaction, $A \to P, t_{1/2}$ (half life) is 10 days. The time required for $\frac{1^{th}}{4}$ conversion of A (in days) is : (ln 2=0.693, ln 3=1.1)

In the extraction of copper from its sulphide ore, metal is finally obtained by the oxidation of cuprous sulphide with :

The INCORRECT statement is :

Which of the following compounds will be suitable for Kjeldahl's method for nitrogen estimation?

Which of the following conversions involves change in both shape and hybridisation?

Which of the following statements is false?

In the molecular orbital diagram for the molecular ion, $N_2{^{+}}$, the number of electrons in the $\sigma_{2p}$ molecular orbital is :

Which of following lines correctly show the temperature dependence of equilibrium constant $K$, for an exothermic reaction ?

Which one of the following is not a property of physical adsorption?

According to molecular orbital theory, which of the following will not be a viable molecule ?

The correct order of spin-only magnetic moments among the following is : (Atomic number : Mn=25, Co=27, Ni=28, Zn=30)

In \(XeO_3F_2\), the number of bond pair(s), \(\pi\)-bond(s) and lone pair(s) on \(Xe\) atom respectively are :

A convergent doublet of separated lenses, corrected for spherical aberration, has resultant focal length of $10 \,cm$. The separation between the two lenses is $2 \,cm$. The focal lengths of the component lenses are :

A body of mass $M$ and charge $q$ is connected to a spring of spring constant $k$. It is oscillating along x-direction about its equilibrium position, taken to be at $x = 0$, with an amplitude $A$. An electric field $E$ is applied along the x-direction. Which of the following statements is correct ?

When an air bubble of radius $r$ rises from the bottom to the surface of a lake, its radius becomes $\frac{5r}{4}$. Taking the atmospheric pressure to be equal to $10\, m$ eight of water column, the depth of the lake would approximately be (ignore the surface tension and the effect of temperature) :

A thin uniform bar of length $L$ and mass $8m$ lies on a smooth horizontal table. Two point masses $m$ and $2m$ are moving in the same horizontal plane from opposite sides of the bar with speeds $2v$ and $v$ respectively. The masses stick to the bar after collision at a distance $\frac{L}{3}$ and $\frac{L}{6}$ respectively from the centre of the bar. If the bar starts rotating about its center of mass as a result of collision, the angular speed of the bar will be :

A telephonic communication service is working at carrier frequency of $10 \,GHz$. Only $10\%$ of it is utilized for transmission. How many telephonic channels can be transmitted simultaneously if each channel requires a bandwidth of $5\, kHz$ ?