List of top Questions asked in JEE Main

A rod is placed along the principal axis as shown. Find the length of the image. The focal length of the mirror is \(f = 10\,\text{cm}\).

Identify the code of amino acid and iodine derivative hormone in the given option.

A container of initial volume $0.15 \text{ m}^3$ is expanded adiabatically from pressure 8 bar to final pressure 1 bar. If initial temperature is $140 \text{ K}$, then find work done by the gas :- ($C_P = 3R, C_V = 2R$) :-

For the given reaction:
CaCO3 + 2HCl → CaCl2 + H2O + CO2

If 90 g CaCO3 is added to 300 mL of HCl which contains 38.55% HCl by mass and has density 1.13 g mL-1,
then which of the following option is correct?

Given molar mass of H, Cl, Ca and O are 1, 35.5, 40 and 16 g mol-1 respectively.

For given Atwood machine. Find displacement (in m) of centre of mass after 2 sec of release.

If \( S_1 \) is closed and \( S_2 \) open, \( \theta \) is 30° and if \( S_1 \) is open and \( S_2 \) closed then \( \theta \) is 60°. Then find \( 3L_2 - L_1 \), if \( C = 100 \mu F \).

Position of a particle is given by \( x = A \sin \left( 50t + \frac{\pi}{3} \right) \). If speed and acceleration become 0 for the first time at \( t_1 \) and \( t_2 \) sec respectively, then find \( t_1 \) and \( t_2 \) (in sec):

At any instant, if \( \vec{B} = -2 \times 10^{-7} \hat{j} \, \text{T} \) and \( \vec{C} \) is along the +x axis, then \( \vec{E} \) at this instant is:

If foot of the perpendicular from a point \( P(a,b,0) \) on the line \( \dfrac{x-1}{2}=\dfrac{y-2}{1}=\dfrac{z-\alpha}{3} \) is \( A \) and mid-point of \( AP \) is \( \left(0,\dfrac{3}{4},-\dfrac{1}{4}\right) \), then the value of \( \left(a^2+b^2+\alpha^2\right) \) is -

For given logic gate circuit, an equivalent gate will be

Arrange the following complexes in increasing order of C.F.S.E. (\( \Delta_0 \))
(a) \( [\text{Co}(\text{H}_2\text{O})_6]^{2+} \)
(b) \( [\text{Co}(\text{H}_2\text{O})_6]^{3+} \)
(c) \( [\text{Co}(\text{en})_3]^{3+} \)

If \( G \) is the Gravitational constant and \( h \) is Planck's constant, then the dimension of \( G \) is:

For first order reaction:
2A(g) → 4B(g) + C(g)
Total pressure at \( t = 30 \, \text{sec} \) and \( t = \infty \) are 300 torr and 600 torr respectively. Calculate pressure of C(g) at 30 sec (in torr).

Parabola \( y = x^2 + px + q \) is passing through \( (1,-1) \) and vertex of parabola is at minimum distance from x-axis then \( p^2 + q^2 \) is

Identify A and E

Which of the following compounds shows coordination isomerism?
(A) \( [\text{Fe(NH}_3)_6] [\text{Co(CN)}_6] \)
(B) \( [\text{Cr(NH}_3)_6] [\text{Co(CN)}_6] \)
(C) \( [\text{Co(NH}_3)_6] [\text{Co(CN)}_6] \)
(D) \( [\text{Ag(NH}_3)_2] [\text{Ag(CN)}_2] \)
(E) \( [\text{Fe(NH}_3)_6] [\text{Cr(CN)}_6] \)

Find sum up to 8 terms of the series
\[ \frac{1^3}{1}+\frac{1^3+2^3}{1+3}+\frac{1^3+2^3+3^3}{1+3+5}+\cdots \]

Find the ratio of electric flux passing through two spheres centered at the origin, having radii 4 m and 6 m respectively, with charges \( q_1 = 8 \, \mu C \) and \( q_2 = 2 \, \mu C \) respectively.

Which of the ions show positive Borax Bead test and has the largest ionization energy:

If \( {}^{30}C_{30-r} + 3 \cdot {}^{30}C_{31-r} + 3 \cdot {}^{30}C_{32-r} + {}^{30}C_{33-r} = {}^{n}C_{r} \), then value of \( n \) is

Statement 1: The correct order of 2\(^\text{nd}\) ionization energy for boron family elements is: \( \text{B}>\text{Al}>\text{Ga} \).
Statement 2: The correct order of 1\(^\text{st}\) ionization energy for carbon family elements is: \( \text{Si}>\text{Ge}<\text{Pb}<\text{Sn} \).
Choose the correct option:

Find \( \frac{BE}{A} \) of \( {}^{83}\text{Bi}^{209} \).
Given: \( M_{\text{Bi}} = 208.9804 \, \text{amu}, \, m_p = 1.007276 \, \text{amu}, \, m_n = 1.008665 \, \text{amu}, \, 1 \, \text{amu} = 931 \, \text{MeV} \)

A metal of work function 2.3 eV is irradiated with radiation of wavelength \( y \times 10^2 \) nm. The maximum kinetic energy of ejected electron is \( 2.8 \times 10^{-20} \) J. Then calculate \( y \) (in nearest integer).