List of top Questions asked in JEE Main

Given below are two statements: 
Statement I: $ H_2Se $ is more acidic than $ H_2Te $ 
Statement II: $ H_2Se $ has higher bond enthalpy for dissociation than $ H_2Te $
In the light of the above statements, choose the correct answer from the options given below.

20 mL of sodium iodide solution gave 4.74 g silver iodide when treated with excess of silver nitrate solution. The molarity of the sodium iodide solution is _____ M. (Nearest Integer value) (Given : Na = 23, I = 127, Ag = 108, N = 14, O = 16 g mol$^{-1}$)

The energy of an electron in first Bohr orbit of H-atom is $-13.6$ eV. The magnitude of energy value of electron in the first excited state of Be$^{3+}$ is _____ eV (nearest integer value)

Consider the following half cell reaction $ \text{Cr}_2\text{O}_7^{2-} (\text{aq}) + 6\text{e}^- + 14\text{H}^+ (\text{aq}) \longrightarrow 2\text{Cr}^{3+} (\text{aq}) + 7\text{H}_2\text{O}(1) $ 
The reaction was conducted with the ratio of $\frac{[\text{Cr}^{3+}]^2}{[\text{Cr}_2\text{O}_7^{2-}]} = 10^{-6}$ 
The pH value at which the EMF of the half cell will become zero is ____ (nearest integer value) 
[Given : standard half cell reduction potential $\text{E}^\circ_{\text{Cr}_2\text{O}_7^{2-}, \text{H}^+/\text{Cr}^{3+}} = 1.33\text{V}, \quad \frac{2.303\text{RT}}{\text{F}} = 0.059\text{V}$

The atomic number of the element from the following with lowest $ 1^{\text{st}} $ ionization enthalpy is:
Which one of the following reactions will not lead to the desired ether formation in major proportion?
(iso-Bu = isobutyl, sec-Bu = sec-butyl, nPr = n-propyl, tBu = tert-butyl, Et = ethyl)

When undergoes intramolecular aldol condensation, the major product formed is:


Choose the correct option for structures of A and B, respectively:

What is the correct IUPAC name of the following compound?


A shows positive Lassaigne's test for N and its molar mass is 121.
B gives effervescence with aqueous NaHCO3. 
C gives fruity smell. 
Identify A, B, and C from the following.

The correct decreasing order of spin only magnetic moment values (BM) of $ \text{Cu}^+ $, $ \text{Cu}^{2+} $, $ \text{Cr}^{2+} $ and $ \text{Cr}^{3+} $ ions is:
A convex lens (f = 30 cm) is in contact with a concave lens (f = -20 cm). An object is placed on the left side at a distance of 20 cm. Find the image distance.
For the function \( f(x) = \ln(x^2 + 1) \), what is the second derivative of \( f(x) \)?
Let $ a $ be the length of a side of a square OABC with O being the origin. Its side OA makes an acute angle $ \alpha $ with the positive $ x $-axis and the equations of its diagonals are $\left( \sqrt{3} + 1 \right) x + \left( \sqrt{3} - 1 \right) y = 0$ and $\left( \sqrt{3} - 1 \right) x - \left( \sqrt{3} + 1 \right) y + 8\sqrt{3} = 0.$ Then $ a^2 $ is equal to
Power of point source is 450 watts. Radiation pressure on a perfectly reflecting surface at a distance of 2 meters is:

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R 
Assertion A: Work done in moving a test charge between two points inside a uniformly charged spherical shell is zero, no matter which path is chosen. 
Reason R: Electrostatic potential inside a uniformly charged spherical shell is constant and is same as that on the surface of the shell. 
In the light of the above statements, choose the correct answer from the options given below

Water falls from a height of 200 m into a pool. Calculate the rise in temperature of the water assuming no heat dissipation from the water in the pool. (Take $ g = 10 \, \text{m/s}^2 $, specific heat of water = 4200 J/(kg K))

Figure shows a current carrying square loop ABCD of edge length is $ a $ lying in a plane. If the resistance of the ABC part is $ r $ and that of the ADC part is $ 2r $, then the magnitude of the resultant magnetic field at the center of the square loop is:

The output voltage in the following circuit is (Consider ideal diode case): 

In a Young's double slit experiment, the source is white light. One of the slits is covered by red filter and another by green filter. In this case,
A concave-convex lens of refractive index 1.5 and the radii of curvature of its surfaces are 30 cm and 20 cm, respectively. The concave surface is upwards and is filled with a liquid of refractive index 1.3. The focal length of the liquid–glass combination will be:
Two balls with the same mass and initial velocity are projected at different angles in such a way that the maximum height reached by the first ball is 8 times higher than that of the second ball. $ T_1 $ and $ T_2 $ are the total flying times of the first and second ball, respectively, then the ratio of $ T_1 $ and $ T_2 $ is:
A block of mass 2 kg is attached to one end of a massless spring whose other end is fixed at a wall. The spring-mass system moves on a frictionless horizontal table. The spring's natural length is 2 m and spring constant is 200 N/m. The block is pushed such that the length of the spring becomes 1 m and then released. At distance $ x $ m ($ x \leq 2 $) from the wall, the speed of the block will be:
A quantity $ Q $ is formulated as $ Q = X^{-2} Y^{3/2} Z^{-2/5} $. $ X $, $ Y $, and $ Z $ are independent parameters which have fractional errors of 0.1, 0.2, and 0.5, respectively in measurement. The maximum fractional error of $ Q $ is:
The amplitude and phase of a wave that is formed by the superposition of two harmonic travelling waves, $ y_1 (x, t) = 4 \sin(kx - \omega t) $ and $ y_2 (x, t) = 2 \sin(kx - \omega t + \frac{2\pi}{3}) $, are: (Take the angular frequency of initial waves same as $ \omega $)