List of top Questions asked in JEE Main

Consider a force \(\vec{F}=-x\hat{i}+y\hat{j}\). The work done by this force in moving a particle from point A(1, 0) to B(0, 1) along the line segment is : (all quantities are in SI units)

One end of a straight uniform 1 m long bar is pivoted on horizontal table. It is released from rest when it makes an angle 30\(^\circ\) from the horizontal (see figure). Its angular speed when it hits the table is given as \(\sqrt{n}\ \mathrm{s^{-1}}\), where \(n\) is an integer. The value of \(n\) is ________.

Consider the following reactions

The mass percentage of carbon in A is ______.

A cylinder containing an ideal gas (0.1 mol of 1.0 \(\mathrm{dm^3}\)) is in thermal equilibrium with a large volume of 0.5 molal aqueous solution of ethylene glycol at its freezing point. If the stoppers \(\mathrm{S_1}\) and \(\mathrm{S_2}\) (as shown in the figure) are suddenly withdrawn, the volume of the gas in litres after equilibrium is achieved will be____.
(Given, \(K_f\) (water) = 2.0 K kg \(\mathrm{mol^{-1}}\), \(R = 0.08\ \mathrm{dm^3\ atm\ K^{-1}\ mol^{-1}}\))

A particle of mass \(m\) and charge \(q\) is released from rest in a uniform electric field. If there is no other force on the particle, the dependence of its speed \(v\) on the distance \(x\) travelled by it is correctly given by (graphs are schematic and not drawn to scale)

An object is gradually moving away from the focal point of a concave mirror along the axis of the mirror. The graphical representation of the magnitude of linear magnification \((m)\) versus distance of the object from the mirror \((x)\) is correctly given by :
(Graphs are drawn schematically and are not to scale)

A very long wire ABDMNDC is shown in figure carrying current \(I\). AB and BC parts are straight, long and at right angle. At D wire forms a circular turn DMND of radius \(R\). AB, BC parts are tangential to circular turn at N and D. Magnetic field at the centre of circle is :

As shown in the figure, a battery of emf \(\varepsilon\) is connected to an inductor \(L\) and resistance \(R\) in series. The switch is closed at \(t = 0\). The total charge that flows from the battery, between \(t = 0\) and \(t = t_c\) (\(t_c\) is the time constant of the circuit) is :

Both the diodes used in the circuit shown are assumed to be ideal and have negligible resistance when these are forward biased. Built in potential in each diode is \(0.7\ \mathrm{V}\). For the input voltages shown in the figure, the voltage (in Volts) at point A is __________.

Identify (A) in the following reaction sequence :

Which of these will produce the highest yield in Friedel Crafts reaction?

The major product (Y) in the following reactions is :

The major product Z obtained in the following reaction scheme is :

The correct order of heat of combustion for following alkadienes is :

The increasing order of basicity for the following intermediates is (from weak to strong)

(i) \((\mathrm{CH_3})_3\mathrm{C}^{\ominus}\)
(ii) \(\mathrm{H_2C=CH-\overset{\ominus}{C}H_2}\)
(iii) \(\mathrm{HC\equiv C^{\ominus}}\)
(iv) \(\overset{\ominus}{\mathrm{C}}\mathrm{H_3}\)
(v) \(\mathrm{{}^{\ominus}CN}\)

As shown in figure, when a spherical cavity (centered at \(O\)) of radius 1 is cut out of a uniform sphere of radius \(R\) (centered at \(C\)), the centre of mass of remaining (shaded) part of sphere is at \(G\), i.e., on the surface of the cavity. \(R\) can be determined by the equation :

Two liquids of densities \(\rho_1\) and \(\rho_2\) (\(\rho_2=2\rho_1\)) are filled up behind a square wall of side 10 m as shown in figure. Each liquid has a height of 5 m. The ratio of the forces due to these liquids exerted on upper part MN to that at the lower part NO is (Assume that the liquids are not mixing)

In the given circuit, value of \(Y\) is :

Among the compounds A and B with molecular formula \(\mathrm{C_9H_{18}O_3}\), A is having higher boiling point the B. The possible structures of A and B are :

The major product [B] in the following sequence of reactions is :-

The major product in the following reaction is:

An unsaturated hydrocarbon X absorbs two hydrogen molecules on catalytic hydrogenation and also gives following reaction :

B (3 - oxo - hexanedicarboxylic acid) X will be :-

In the following sequence of reactions the maximum number of atoms present in molecule 'C' in one plane is _________.

(A is a lowest molecular weight alkyne)

The graph which depicts the results of Rutherford gold foil experiment with \(\alpha\)-particales is :
\(\theta\) : Scattering angle
Y : Number of scattered \(\alpha\)-particles detected (Plots are schematic and not to scale)

Boolean relation at the output stage-Y for the following circuit is :