List of top Questions asked in JEE Main

A capacitor is made of two square plates each of side $'a'$ making a very small angle a between them, as shown in figure. The capacitance will be close to :

An amplitude modulated wave is represented by the expression $v _{ m }=5(1+0.6 \cos 6280 t )$ $\sin \left(211 \times 10^{4} t \right)$ volts. The minimum and maximum amplitudes of the amplitude modulated wave are, respectively :

A particle is moving unidirectionally on a horizontal plane under the action of a constant power supplying energy source. The displacement (s) - time (t) graph that describes the motion of the particle is (graphs are drawn schematically and are not to scale) :

A quantity $x$ is given by $(IFv^2 / WL^{4})$ in terms of moment of inertia $I, $ force $ F$, velocity $v ,$ work $W$ and Length $L$. The dimensional formula for $x$ is same as that of :

Model a torch battery of length $l$ to be made up of a thin cylindrical bar of radius $'a'$ and a concentric thin cylindrical shell of radius $'b'$ filled in between with an electrolyte of resistivity $\rho$ (see figure). If the battery is connected to a resistance of value $R ,$ the maximum Joule heating in $R$ will take place for :

In the following reactions sequence, structure of A and B respectively will be :

Identify the operation performed by the circuit given below :

The value of current \(i_1\) flowing from A to C in the circuit diagram is :

For a uniform rectangular sheet shown in the figure, the ratio of moments of inertia about the axes perpendicular to the sheet and passing through O (the centre of mass) and O' (corner point) is :

In a photoelectric effect experiment, the graph of stopping potential V versus reciprocal of wavelength obtained is shown in the figure. As the intensity of incident radiation is increased :

Four resistances 40 \(\Omega\), 60 \(\Omega\), 90 \(\Omega\) and 110 \(\Omega\) make the arms of a quadrilateral ABCD. Across AC is a battery of emf 40 V and internal resistance negligible. The potential difference across BD in V is _______.

The speed verses time graph for a particle is shown in the figure. The distance travelled (in m) by the particle during the time interval t = 0 to t = 5 s will be________.

Which of the following compounds will form the precipitate with aq. AgNO₃ solution most readily?

The major product [C] of the following reaction sequence will be :
\(\mathrm{CH_2{=}CH{-}CHO}\ \xrightarrow[\mathrm{(ii)\ SOCl_2}]{\mathrm{(i)\ NaBH_4}}\ \mathrm{[A]}\ \xrightarrow[\mathrm{Anhy.\ AlCl_3}]{\mathrm{Benzene}}\ \mathrm{[B]}\ \xrightarrow{\mathrm{DBr}}\ \mathrm{[C]}\)

In the following reaction sequence, [C] is :

(Sequence: p-toluidine, (i) \(\mathrm{NaNO_2 + HCl}\), \(0-5^\circ\mathrm{C}\); (ii) \(\mathrm{Cu_2Cl_2 + HCl}\) gives [A]; [A] with \(\mathrm{Cl_2}\), \(h\nu\) gives [B]; [B] with Na + dry ether gives [C] (Major Product).)

Among the following compounds, which one has the shortest C - Cl bond?

Take the breakdown voltage of the zener diode used in the given circuit as 6V. For the input voltage shown in figure below, the time variation of the output voltage is :
(Graphs drawn are schematic and not to scale)

Two charged thin infinite plane sheets of uniform surface charge density \(\sigma_+\) and \(\sigma_-\), where \(|\sigma_+| \gt |\sigma_-|\), intersect at right angle. Which of the following best represents the electric field lines for this system :

A wire A, bent in the shape of an arc of a circle, carrying a current of 2 A and having radius 2 cm and another wire B, also bent in the shape of arc of a circle, carrying a current of 3 A and having radius of 4 cm, are placed as shown in the figure. The ratio of the magnetic fields due to the wires A and B at the common centre O is :

A small bar magnet is moved through a coil at constant speed from one end to the other. Which of the following series of observations will be seen on the galvanometer G attached across the coil ?

Three positions shown describe : (a) the magnet's entry (b) magnet is completely inside and (c) magnet's exit.

A Tennis ball is released from a height \(h\) and after freely falling on a wooden floor it rebounds and reaches height \(\frac{h}{2}\). The velocity versus height of the ball during its motion may be represented graphically by :
(graph are drawn schematically and on not to scale)

Blocks of masses \(m\), \(2m\), \(4m\) and \(8m\) are arranged in a line on a frictionless floor. Another block of mass \(m\), moving with speed \(v\) along the same line (see figure) collides with mass \(m\) in perfectly inelastic manner. All the subsequent collisions are also perfectly inelastic. By the time the last block of mass \(8m\) starts moving the total energy loss is \(p\%\) of the original energy. Value of 'p' is close to :

ABC is a plane lamina of the shape of an equilateral triangle. D, E are mid points of AB, AC and G is the centroid of the lamina. Moment of inertia of the lamina about an axis passing through G and perpendicular to the plane ABC is \(I_0\). If part ADE is removed, the moment of inertia of the remaining part about the same axis is \(\frac{NI_0}{16}\) where N is an integer. Value of N is ____.

\(E^{\circ}_{\mathrm{Cu^{2+}|Cu}} = +0.34\ \mathrm{V}\)
\(E^{\circ}_{\mathrm{Zn^{2+}|Zn}} = -0.76\ \mathrm{V}\)
Identify the incorrect statement from the options below for the above cell :

For the equilibrium \(\mathrm{A} \rightleftharpoons \mathrm{B}\), the variation of the rate of the forward (a) and reverse (b) reaction with time is given by :