List of top Questions asked in JEE Main

In the long form of the periodic table, the valence shell electronic configuration of $5s^2 5p^4$ corresponds to the element present in :
Locus of the image of the point $(2, 3)$ in the line $\left(2x - 3y + 4\right) + k\left(x - 2y + 3\right) = 0, k \in R,$ is a
An ellipse passes through the foci of the hyperbola, $9x^2? 4y^2 = 36$ an and minor axes lie along the transverse and conjugate axes of the hyperbola respectively. If the product of eccentricities of the two conics is $\frac{1}{2},$ then which of the following points does not lie on the ellipse ?
The least number of oxyacids are formed by :
An experiment takes $10\, min$ to raise the temperature of water in a container from $0^{\circ} C$ to $100^{\circ} C$ and another $55\, min$ to convert it totally into steam by a heater supplying heat at a uniform rate. Neglecting the specific heat of the container and taking specific heat of water to be $1\, cal / g { }^{\circ} C$, the heat of vaporisation according to this experiment will come out to be
A person climbs up a stalled escalator in $60\, s$ . If standing on the same but escalator running with constant velocity he takes $40\, s$. How much time is taken by the person to walk up the moving escalator ?
The total number of octahedral void(s) per atom present in a cubic close packec structure is :-
A particle moves with simple harmonic motion in a straight line. In first $\tau$ sec, after starting from rest it travels a distance a and in next $\tau$ sec, it travels $2a$, in same direction, then
The initial speed of a bullet fired from a rifle is $630\, m/ s$. The rifle is fired at the centre of a target $700\, m$ away at the same level as the target. How far above the centre of the target the rifle must be aimed in order to hit the target ?
A transmitting antenna at the top of a tower has a height $32 \,m$ and the height of the receiving antenna is $50 \,m$. What is the maximum distance between them for satisfactory communication in line of sight (LOS) mode ?
Match List -1 (Electromagnetic wave type) with List - II (Its association/application) and select the correct option from the choices given below the lists :
An $n-p-n$ transistor has three leads $A, B$ and $C$. Connecting $B$ and $C$ by moist fingers, $A$ to the positive lead of an ammeter, and $C$ to the negative lead of the ammeter, one finds large deflection. Then, $A, B$ and $C$ refer respectively to :
The integral $\int^{^{\frac{1}{2}}}_{_0} \frac{ln \left(1+2x\right)}{1+4x^{2}}dx,$ equals :
The most suitable reagent for the conversion of $RCH_2OH \to RCHO$ is
The velocity of water in a river is $18\, km/hr$ near the surface. If the river is $5\, m$ deep, find the shearing stress between the horizontal layers of water. The co-efficient of viscosity of water $= 10^{-2}$ poise.
The coefficient of $x^{1012}$ in the expansion of $(1 + x^n + x^{253})^{10}$, (where n $\le$ 22 is any positive integer), is :-
The minimum area of a triangle formed by any tangent to the ellipse $\frac{x^{2}}{16}+\frac{y^{2}}{81}=1$ and the co-ordinate axes is :
The variance of first $50$ even natural numbers is
In the Victor-Meyer's test, the colour given by $1^{\circ}$, $2^{\circ}$and $3^{\circ}$ alcohols are respectively :
Given an $A.P$. whose terms are all positive integers. The sum of its first nine terms is greater than $200$ and less than $220$. If the second term in it is $12$, then its $4^{th}$ term is :
A Zener diode is connected to a battery and a load as shown below : The currents $I, I_z$ and $I_L$ are respectively
The angle between the lines whose direction cosines satisfy the equations $l + m + n = 0 $ and $ l^2= m^2 + n^2 $is
Tischenko reaction is a modification of :
Two soap bubbles coalesce to form a single bubble. If $V$ is the subsequent change in volume of contained air and $S$ the change in total surface area, $T$ is the surface tension and $P$ atmospheric pressure, which of the following relation is correct ?
For the compounds $CH_3Cl, \, CH_3Br,\,CH_3I$ and $CH_3F,$ the correct order of increasing $C$-halogen bond length is :