List of top Questions asked in JEE Main

Refining using liquation method is the most suitable for metals with :

Which of the following can be used to prevent the decomposition of $H _2 O _2$ ?

Reaction of \(BeCl _2\) with \(LiAlH _4\) gives: Choose the correct answer from options given below : 

1. \(AlCl _3\)
2. \(BeH _2\)
3. \(LiH\)
4. \(LiCl\)
5. \(BeAlH _4\)
    

Borazine, also known as inorganic benzene, can be prepared by the reaction of 3-equivalents of "$X$" with 6-equivalents of "Y". "X" and "Y", respectively are :

The difference in the reaction of phenol with bromine in chloroform and bromine in water medium is due to :

Which technique among the following, is most appropriate in separation of a mixture of $100\, mg$ of $p$-nitrophenol and picric acid ?

$\dot{ C } l + CH _4 \rightarrow A + B$. $A$ and $B$ in the above atmospheric reaction step are

The dark purple colour of $KMnO _4$ disappears in the titration with oxalic acid in acidic medium. The overall change in the oxidation number of manganese in the reaction is :

The force required to stretch a wire of cross-section $1 cm ^2$ to double its length will be: (Given Yong's modulus of the wire $=2 \times 10^{11} N / m ^2$ )

If the radius of earth shrinks by $2 \%$ while its mass remains same The acceleration due to gravity on the earth's surface will approximately :

During the denaturation of proteins, which of these structures will remain intact ?

The photochemical smog does not generally contain :

Choose the correct order of density of the alkali metals :

The compound(s) that is(are) removed as slag during the extraction of copper is : 

1. \(CaO\) 
2.  \(FeO\) 
3.  \(Al _2 O _3\) 
4.  \(ZnO\)
5.  \(NiO\) 
   Choose the correct answer from the options given below :

In two different experiments, an object of mass $5\, kg$ moving with a speed of $25 \,ms ^{-1}$ hits two different walls and comes to rest within
(i) 3 second, 
(ii) 5 seconds, respectively.
Choose the correct option out of the following :

Given below are two statements :
Statement I: In polluted water values of both dissolved oxygen and BOD are very low.
Statement II: Eutrophication results in decrease in the amount of dissolved oxygen.
In the light of the above statements, choose the most appropriate answer from the options given below :

 NCC parade is going at a uniform speed of $9\, km / h$ under a mango tree on which a monkey is sitting at a height of $196\, m$ At any particular instant, the monkey drops a mango A cadet will receive the mango whose distance from the tree at time of drop is : (Given g= 9.8 m/s²)

The dimensions of $\left(\frac{ B ^2}{\mu_0}\right)$ will be :(if $\mu_0$ : permeability of free space andB : magnetic field)

Let $f: R \rightarrow R$ be defined as, $f(x) = \begin{cases} -55x, & \text{if } x < -5 \\ 2x^3 -3x^2 -120x, & \text{if } 5 \le x \le 4 \\ 2x^3 -3x^2-36x-336& \text{if } x > 4, \end{cases} $ Let $A=\{ x \in R : f$ is increasing $\} .$ Then $A$ is equal to

In Freundlich adsorption isotherm, slope of AB line is :

In the given figure, the energy levels of hydrogen atom have been shown along with some transitions marked $A , B , C , D$ and $E$. The transitions $A, B$ and $C$ respectively represent :

Match List -I with List -II

List - I		List -II
a	Isothermal	i	Pressure constant
b	Isobaric	ii	Temperature constant
c	Adiabatic	iii	Volume constant
d	Isobaric	iv	Heat content is constant

Choose the correct answer from the options given below

An LCR circuit contains resistance of $110 \Omega$ and a supply of $220 V$ at $300 rad / s$ angular frequency. If only capacitance is removed from the circuit, current lags behind the voltage by $45^{\circ} .$ If on the other hand, only inductor is removed the current leads by $45^{\circ}$ with the applied voltage. The $rms$ current flowing in the circuit will be :

The negative of the statement $\sim p \wedge( p \vee q )$ is