List of top Questions asked in JEE Main

Water falls from a height of 200 m. What is the increase in temperature when it touches the bottom? (Assume that all the heat goes into the same amount of mass which was falling).
An electron is released in the field generated by a non-conductivity sheet of uniform surface charge density $ \sigma $. The rate of change of de-Broglie wavelength associated with the electron varies inversely as the $ n $th power of the distance travelled. Find the value of $ n $.
Given $ \lambda = 2 \, \text{nC/m} $ (linear charge density) for a wire passing through the body diagonal of a closed cube with side length $ \sqrt{3} \, \text{cm} $, find the flux through the cube.
A monoatomic gas is stored in a thermally insulated container. The gas is suddenly compressed to $ \frac{1}{8} $th of its initial volume. Find the ratio of final pressure to initial pressure.
Two balls are projected with the same speed at different angles. If the maximum height of the 1st ball is 8 times the maximum height of the 2nd ball, find the ratio of their time of flight.
A uniform disc of radius $ r $ is rotating about an axis passing through its diameter with angular speed 800 rpm. A torque of magnitude $ 25\pi \, \text{Nm} $ is applied on the disc for 40 sec. If the final angular speed of the disc is 2100 rpm, find the diameter of the disc if its mass is 1 kg.
For a nucleus of mass number $ A $ and radius $ R $, mass density is $ \rho $. Then choose the correct option.
A fractional error in $ x $, $ y $, and $ z $ are 0.1, 0.2, and 0.5 respectively. Find the maximum fractional error in $ x^{-2} y^{3/2} z^{-2/5} $.
In 3, 3-dimethylhex-1-en-4-yne, the number of sp, sp² and sp³ carbon atoms, respectively are:

Nature of compounds TeO₂ and TeH₂ is___________ and ______________respectively.

For the reaction, $H_2(g) + I_2(g) \rightleftharpoons 2HI(g)$

Attainment of equilibrium is predicted correctly by: 


 
 

In YDSE, light of intensity 4I and 9I passes through two slits respectively. The difference of maximum and minimum intensity of the interference pattern is:
Let $f: [0, 3] \to A$ be defined by $f(x) = 2x^3 - 15x^2 + 36x + 7$ and $g: [0, \infty) \to B$ be defined by $g(x) = \frac{x}{x^{2025} + 1}$. If both functions are onto and $S = \{ x \in \mathbb{Z} : x \in A \text{ or } x \in B \}$, then $n(S)$ is equal to:
Total number of nucleophiles from the following is: $NH_3$, $PhSH$, $(H_3C_2S)_2$, $H_2C=CH_2$, $OH^-$, $H_3O^+$, $(CH_3)_2CO$, $NCH_3$
The figure shows a circular portion of radius \( \frac{R}{2} \) removed from a disc of mass \( m \) and radius \( R \). The moment of inertia about an axis passing through the centre of mass of the disc and perpendicular to the plane is:
If the square of the shortest distance between the lines $$ \frac{x-2}{1} = \frac{y-1}{2} = \frac{z+3}{-3} \quad \text{and} \quad \frac{x+1}{2} = \frac{y+3}{4} = \frac{z+5}{-5}, $$ is $ \frac{m}{n} $, where $m, n$ are coprime numbers, then $m+n$ is equal to:
The number of rational terms in the binomial expansion of $\left( \frac{1}{2} + \frac{1}{8} \right)^{1016}$ is
Which of the following has $\text{sp}^3\text{d}^2$ hybridisation?
Given the series
$\frac{1}{1^4} + \frac{1}{2^4} + \frac{1}{3^4} + \cdots = \frac{\pi^4}{90},$
$\frac{1}{1^4} + \frac{1}{3^4} + \frac{1}{5^4} + \cdots = \alpha,$
$\frac{1}{2^4} + \frac{1}{4^4} + \frac{1}{6^4} + \cdots = \beta.$
Then find $\frac{\alpha}{\beta}$
A convex lens $(f = 30 \, \text{cm})$ is in contact with a concave lens $(f = 20 \, \text{cm}).$ The object is placed on the left side at a distance of $20 \, \text{cm}.$ Find the image distance.
 
A monoatomic gas is stored in a thermally insulated container. The gas is suddenly compressed to $$\frac{1}{8}$$ of its initial volume. Find the ratio of final pressure to initial pressure.
Two balls are projected with the same speed at different angles. If the maximum height of the first ball is 2 times the maximum height of the second ball, find the ratio of their time of flight.
There are 12 points in a plane in which 5 are collinear such that no three of them are in a straight line. Then, the number of triangles that can be formed from any 3 vertices from 12 points.
Atomic number of element with lowest first ionisation enthalpy is
Find the dimension of \( \frac{E}{B} \) where, E represents electric field and B represents magnetic field.