List of top Questions asked in JEE Main

Which of the following polymer is a polyamide ?

Which of the following is the product of aldol condensation?

Identify the incorrect statement:

The magnetic moment of the complex anion \([\mathrm{Cr(NO)(NH_3)(CN)_4}]^{2-}\) is :

When a small amount of \(\mathrm{KMnO_4}\) is added to concentrated \(\mathrm{H_2SO_4}\), a green oily compound is obtained which is highly explosive in nature. Compound may be :

Smoke is an example of :

Identify incorrect statement :

Given :
\(E^\circ_{\frac{1}{2}\mathrm{Cl_2/Cl^-}} = 1.36\ \mathrm{V},\ E^\circ_{\mathrm{Cr^{3+}/Cr}} = -0.74\ \mathrm{V}\)
\(E^\circ_{\mathrm{Cr_2O_7^{2-}/Cr^{3+}}} = 1.33\ \mathrm{V},\ E^\circ_{\mathrm{MnO_4^-/Mn^{2+}}} = 1.51\ \mathrm{V}\)
The correct order of reducing power of the species \((\mathrm{Cr, Cr^{3+}, Mn^{2+}}\) and \(\mathrm{Cl^-})\) will be :

The numbers of protons, electrons and neutrons in a molecule of heavy water are respectively :

Which of the following statements/relationships is not correct in thermodynamic changes ?

What is the pH of a \(10^{-4}\ \mathrm{M\ OH^-}\) solution at 330 K, if \(K_w\) at 330 K is \(10^{-13.6}\) ?

Which of the following statement is NOT correct?

Which is the correct order of second ionization potential of \(\mathrm{C, N, O}\) and \(\mathrm{F}\) in the following ?

The de Broglie wavelength of a car of mass 1000 kg and velocity 36 km/hr is :

The shape of \(\mathrm{IF_6^-}\) is :

In the Bohr's model of hydrogen-like atom the force between the nucleus and the electron is modified as \(F=\dfrac{e^2}{4\pi\varepsilon_0}\left(\dfrac{1}{r^2}+\dfrac{\beta}{r^3}\right)\), where \(\beta\) is a constant. For this atom, the radius of the \(n^{th}\) orbit in terms of the Bohr radius \(\left(a_0=\dfrac{\varepsilon_0h^2}{m\pi e^2}\right)\) is :

Electrons are accelerated through a potential difference V and protons are accelerated through a potential difference 4 V. The de-Broglie wavelengths are \(\lambda_e\) and \(\lambda_p\) for electrons and protons respectively. The ratio of \(\frac{\lambda_e}{\lambda_p}\) is given by: (given \(m_e\) is mass of electron and \(m_p\) is mass of proton).

A system of four gates is set up as shown. The 'truth table' corresponding to this system is :

This question has Statement-1 and Statement-2. Of the four choices given after the Statements, choose the one that best describes the two Statements.
Statement 1: Very large size telescopes are reflecting telescopes instead of refracting telescopes.
Statement 2: It is easier to provide mechanical support to large size mirrors than large size lenses.

\(n\) identical waves each of intensity \(I_0\) interfere with each other. The ratio of maximum intensities if the interference is (i) coherent and (ii) incoherent is :

The plot given below is of the average power delivered to an LRC circuit versus frequency. The quality factor

of the circuit is :

Which of the four resistances \(P, Q, R\) and \(S\) generate the greatest amount of heat when a current flows from A

to B ?

A rectangular loop of wire, supporting a mass \(m\), hangs with one end in a uniform magnetic field \(\vec{B}\) pointing out of the plane of the paper. A clockwise current is set up such that \(i \gt mg/Ba\), where \(a\) is the width of the loop.

Then :

A particle of charge \(16\times10^{-16}\) C moving with velocity 10 ms\(^{-1}\) along \(x\)-axis enters a region where magnetic field of induction \(\vec{B}\) is along the \(y\)-axis and an electric field of magnitude \(10^{4}\) Vm\(^{-1}\) is along the negative \(z\)-axis. If the charged particle continues moving along \(x\)-axis, the magnitude of \(\vec{B}\) is :

A liquid drop having 6 excess electrons is kept stationary under a uniform electric field of 25.5 kVm\(^{-1}\). The density of liquid is \(1.26\times10^{3}\) kg m\(^{-3}\). The radius of the drop is (neglect buoyancy).