List of top Questions asked in JEE Main

Temperature difference of \(120^{\circ}C\) is maintained between two ends of a uniform rod \(AB\) of length \(2L\). Another bent rod \(PQ\), of same cross section as \(AB\) and length \(\frac{3L}{2}\) , is connected across \(AB\) (See figure). In steady state, temperature difference between \(P\) and \(Q\) will be close to :
Another bent rod PQ, of same cross section as AB and length 3L/2, is connected across AB
The combination of plots which does not represent isothermal expansion of an ideal gas is:
The contrapositive of the statement "If you are born in India, then you are a citizen of India", is :
The energy required to take a satellite to a height $'h'$ above Earth surface (radius of Earth = $6.4 \times 10^3 \; km) $ is $E_1$ and kinetic energy required for the satellite to be in a circular orbit at this height is $E_2$. The value of $h$ for which $E_1 $ and $E_2$ are equal, is:
The magnitude of torque on a particle of mass $1\,kg$ is $2.5\, Nm$ about the origin. If the force acting on it is $1\, N$, and the distance of the particle from the origin is $5\,m$, the angle between the force and the position vector is (in radians) :
The number density of molecules of a gas depends on their distance r from the origin as, $n(r) = n_0e^{-\alpha r^4}$ Then the total number of molecules is proportional to :
The output of the given logic circuit is :
The variation of refractive index of a crown glass thin prism with wavelength of the incident light is shown. Which of the following graphs is the correct one, if $D_m$ is the angle of minimum deviation?
There are two long co-axial solenoids of same length $l$. the inner and outer coils have radii $r_1$ and $r_2$ and number of turns per unit length $n_1$ and $n_2$ respectively. The rate of mutual inductance to the self-inductance of the inner-coil is :
$ \lim\limits_{n \to \infty}$$\frac{3}{n}\left\{1+\sqrt{\frac{n}{n+3}}+\sqrt{\frac{n}{n+6}}+\sqrt{\frac{n}{n+9}}+....+\sqrt{\frac{n}{n+3\left(n-1\right)}}\right\}$
The area of the region $A = [(x, y): 0 \leq y \leq x|x|+1$ and $-1 \leq x \leq 1]$ in s units is :
In a random experiment, a fair die is rolled until two fours are obtained in succession. The probability that the experiment will end in the fifth throw of the die is equal to :
In the cell ${Pt(s) | H_2(g , 1 bar | HCl(aq) | Ag(s) | Pt(s)} $ the cell potential is 0.92 when a $10^{-6}$ molal HCl solution is used. THe standard electrode potential of ${(AgCl/Ag,Cl^{-})}$ electrode is : $\left\{ \text{given} , \frac{2.303RT}{F} = 0.06 V \; at \; 298K\right\}$
The structures of beryllium chloride in the solid state and vapour, phase, respectively,are :
Three Carnot engines operate in series between a heat source at a temperature $T_1$ and a heat sink at temperature $T_4$ (see figure). There are two other reservoirs at temperature $T_2$, and $T_3$, as shown, with $T_2 > T_2 > T_3 > T_4$ . The three engines are equally efficient if:
Two blocks $A$ and $B$ of masses $m_A = 1 \; kg$ and $m_B = 3 \; kg$ are kept on the table as shown in figure. The coefficient of friction between $A$ and $B$ is $0.2$ and between $B$ and the surface of the table is also $0.2.$ The maximum force $F$ that can be applied on $B$ horizontally, so that the block $A$ does not slide over the block $B$ is : (Take $g = 10 \; m/s^2$)
Two coherent sources produce waves of different intensities which interfere. After interference, the ratio of the maximum intensity to the minimum intensity is $16$. The intensity of the waves are in the ratio:
Two solids dissociate as follows $ {A(s) <=> B(g) + C(g) ; K_{p_1} = x \; atm^2}$ $ {D(s) <=> C(g) + E(g) ; K_{p_2} = y \; atm^2}$ The total pressure when both the solids dissociate simultaneously is :
An element has a face-centred cubic (fcc ) structure with a cell edge of a. The distance between the centres of two nearest tetrahedral voids in the lattice is :
A $10\, mg$ effervescent tablet contianing sodium bicarbonate and oxalic acid releases $0.25\, ml$ of ${CO_2}$ at $T$ = $298.15\, K$ and $p = 1$ bar. If molar volume of ${CO_2}$ is $25.0\, L$ under such condition, what is the percentage of sodium bicarbonate in each tablet ? [Molar mass of ${NaHCO_3 = 84 \; g \; mol^{-1}}$]
An urn contains $5$ red and $2$ green balls. A ball is drawn at random from the urn. If the drawn ball is green, then a red ball is added to the urn and if the drawn ball is red, then a green ball is added to the urn; the original ball is not returned to the urn. Now, a second ball is drawn at random from it. The probability that the second ball is red, is :
Axis of a parabola lies along $x$-axis. If its vertex and focus are at distances $2$ and $4$ respectively from the origin, on the positive $x$-axis then which of the following points does not lie on it ?
Determine the electric dipole moment of the system of three charges, placed on the vertices of an equilateral triangle, as shown in the figure:
Given $\frac{b+c}{11} = \frac{c+a}{12}= \frac{a+b}{13} $ for a $ \Delta ABC$ with usual notation. If $ \frac{\cos A}{\alpha} = \frac{\cos B}{\beta} = \frac{\cos C}{\gamma} $ , then the ordered triad $( \alpha, \beta, \gamma)$ has a value :
If in a parallelogram $ABDC$, the coordinates of $A, B$ and $C$ are respectively $(1, 2), (3, 4)$ and $(2, 5),$ then the equation of the diagonal $AD$ is :