List of top Questions asked in JEE Main

In an experiment a sphere of aluminium of mass 0.20 kg is heated upto $150^{\circ}C$. Immediately, it is put into water of volume 150 cc at $27^{\circ}C$ kept in a calorimeter of water equivalent to 0.025 kg. Final temperature of the system is $40^{\circ}C$. The specific heat of aluminium is : (take 4.2 Joule=1 calorie)

1 gram of a carbonate $(M_2CO_3)$ on treatment with excess $HCl$ produces $0.01186$ mole of $CO_2$. The molar mass of $M_2CO_3$ in g $mol^{-1}$ is :

Excess of $NaOH_{(aq)}$ was added to $100\, mL$ of ${ FeCl_3}$ (aq) resulting into $2.14\, g$ of ${Fe(OH)_3}$. The molarity of ${FeCl_3}$ (aq) is : (Given molar mass of ${Fe = 56 \, g \, mol^{-1}}$ and molar mass of ${Cl = 35.5 \, g \, mol^{-1}}$)

Let $l_n = \int \tan^{n} x \, dx , (n > 1) . l_4 + l_6 = a \, \, \tan^5 \, x + bx^5 + C$, where $C$ is a constant of integration, then the ordered pair $(a, b)$ is equal to :

An observer is moving with half the speed of light towards a stationary microwave source emitting waves at frequency $10\, GHz$. What is the frequency of the microwave measured by the observer ? (speed of light $= 3 \times 10^8 \, ms^{-1}$)

A slender uniform rod of mass $M$ and length $l$ is pivoted at one end so that it can rotate in a vertical plane (see figure). There is negligible friction at the pivot. The free end is held vertically above the pivot and then released. The angular acceleration of the rod when it makes an angle $\theta$ with the vertical is :

An external pressure \(P\) is applied on a cube at \(0^{\circ}C\) so that it is equally compressed from all sides.\(K\) is the bulk modulus of the material of the cube and \(\alpha\) is its coefficient of linear expansion.Suppose we want to bring the cube to its original size by heating it. The temperature should be raised by :

The integral $\int\limits^{\frac{3\, \pi}{4}}_{\frac{\pi}{4}} \frac{dx}{ 1 + \cos \, x}$ is equal to :

For a reaction, $ {A_(g) \to A_(l); \Delta H = - 3RT}$. The correct statement for the reaction is :

In an experiment a convex lens of focal length $15\, cm$ is placed coaxially on an optical bench in front of a convex mirror at a distance of $5 \,cm$ from it. It is found that an object and its image coincide, if the object is placed at a distance of $20 \,cm $ from the lens. The focal length of the convex mirror is :

$C_p$ and $C_v$ are specific heats at constant pressure and constant volume respectively. It is observed that $C_p-C_v$ = a for hydrogen gas $C_p-C_v$ = b for nitrogen gas The correct relation between $a$ and $b$ is :

$sp^3d^2$ hybridization is not displayed by :

$\displaystyle\lim_{x \to \frac{\pi}{2}} \frac{\cot x - \cos x}{\left(\pi - 2x\right)^{3}} $ equals :

A sinusoidal voltage of peak value $283\, V$ and angular frequency $320/s$ is applied to a series $LCR$ circuit. Given that $R = 5 \, \Omega , L = 25 \, mH $ and $C=1000 \, \mu F$. The total impedance, and phase difference between the voltage across the source and the current will respectively be :

A physical quantity $P$ is described by the relation $P = a^{1/2} b^2 c^3 d^{-4} $ If the relative errors in the measurement of $a, b, c$ and $d$ respectively, are $2\%, 1\%, 3\%$ and $5\%$, then the relative error in $P$ will be :

The current gain of a common emitter amplifier is $69$ . If the emitter current is $7.0 \,mA$, collector current is :

The energy stored in the electric field produced by a metal sphere is $4.5\, J$. If the sphere contains $ 4 \, \mu C$ charge, its radius will be : [Take : $\frac{1}{4 \pi \epsilon_o } = 9 \times 10^{9} \, N - m^2 / C^2$ ]

$2$ moles of an ideal monatomic gas is carried from a state $(P_0, V_0)$ to a state $(2P_0, 2V_0)$ along a straight line path in a P-V diagram. The amount of heat absorbed by the gas in the process is given by

The group having triangular planar structures is :

The electron in the hydrogen atom undergoes transition from higher orbitals to orbital of radius $211.6\, pm$. This transition is associated with

The area (in s units) of the region $\{ (x , y) : x \geq 0 , x + y \leq 3, x^2 \leq 4 y$ and $y \leq 1 + \sqrt{x} \}$ is

If two different numbers are taken from the set $\{0,1,2,3, \ldots \ldots, 10\}$then the probability that their sum as well as absolute difference are both multiple of $4$, is :

Let $S_{n} = \frac{1}{1^{3}} + \frac{1+2}{1^{3} + 2^{3}} + \frac{1+2+3}{1^{3} + 2^{3} + 3^{3}} + ...... + \frac{1+2+...+n}{1^{3} + 2^{3} +.... +n^{3}} . $ . If $100 \, S_n = n , $ then $n$ is equal to :

Let $z \in C$, the set of complex numbers. Then the equation, $2 | z + 3i| - | z - i| = 0 $ represents :

An unbiased coin is tossed eight times. The probability of obtaining at least one head and at least one tail is :