List of top Questions asked in JEE Main- 2019

The correct match between Item I and Item II is :

Item I		Item II
(A)	Ester test	(P)	Tyr
(B)	Carbylamine test	(Q)	Asp
(C)	Phthalein dye test	(R)	Ser
		(S)	Lys

The de Broglie wavelength (\(\lambda\)) associated with a photoelectron varies with the frequency (\(\nu\)) of the incident radiation as, [\(\nu_0\) is threshold frequency] :

For the equilibrium, \(2\mathrm{H_2O} \rightleftharpoons \mathrm{H_3O^+} + \mathrm{OH^-}\), the value of \(\Delta G^\circ\) at 298 K is approximately :

The major product obtained in the following conversion is

The correct option with respect to the Pauling electronegativity values of the element is :

25 ml of the given HCl solution requires 30 mL of 0.1 M sodium carbonate solution. What is the volume of this HCl solution required to titrate 30 mL of 0.2 M aqueous NaOH solutions ?

The reaction \(2\mathrm{X} \rightarrow \mathrm{B}\) is a zeroth order reaction. If the initial concentration of X is 0.2 M, the half-life is 6 h. When the initial concentration of X is 0.5 M, the time required to reach its final concentration of 0.2 M will be:

The standard reaction Gibbs energy for a chemical reaction at an absolute temperature T is given by \(\Delta_rG^{o} = A - BT\)
Where A and B are non-zero constants. Which of the following is TRUE about this reaction?

A compound 'X' on treatment with \(\mathrm{Br_2/NaOH}\), provided \(\mathrm{C_3H_9N}\), which gives positive carbylamine test. Compound 'X' is :

In the following compound,

the favourable site/s for protonation is/are :

Which of the following compounds reacts with ethylmagnesium bromide and also decolourizes bromine water solution:

\(A \xrightarrow{4KOH,\ O_2} \underset{(\mathrm{Green})}{2B} + 2H_2O\)
\(3B \xrightarrow{4HCl} \underset{(\mathrm{Purple})}{2C} + MnO_2 + 2H_2O\)
\(2C \xrightarrow{H_2O.KI} \underset{(\mathrm{Purple})}{2A} + 2KOH + D\)
In the above sequence of reactions, A and D, respectively, are :

The coordination number of Th in \(\mathrm{K_4[Th(C_2O_4)_4(OH_2)_2]}\) is :
\(\left(\mathrm{C_2O_4^{2-}} = \text{Oxalato}\right)\)

The major product of the following reaction is :

The major product obtained in the following reaction is :

Given the equilibrium constant:
\(K_C\) of the reaction :
\(\mathrm{Cu(s) + 2Ag^{+}(aq) \rightarrow Cu^{2+}(aq) + 2Ag(s)}\) is \(10\times10^{15}\), calculate the \(E^{0}_{cell}\) of this reaction at 298 K
\(\left[2.303\,\frac{RT}{F}\ \text{at 298 K} = 0.059\ \mathrm{V}\right]\)

A particle of mass m and charge q is in an electric and magnetic field given by
\(\vec{E} = 2\hat{i} + 3\hat{j};\ \vec{B} = 4\hat{j} + 6\hat{k}\).
The charged particle is shifted from the origin to the point P(x = 1; y = 1) along a straight path. The magnitude of the total work done is :

A particle of mass m is moving in a straight line with momentum p. Starting at time t = 0, a force F = kt acts in the same direction on the moving particle during time interval T so that its momentum changes from p to 3p. Here k is a constant. The value of T is :

A galvanometer having a resistance of \(20\ \Omega\) and 30 divisions on both sides has figure of merit 0.005 ampere/division. The resistance that should be connected in series such that it can be used as a voltmeter upto 15 volt, is:

A pendulum is executing simple harmonic motion and its maximum kinetic energy is \(K_1\). If the length of the pendulum is doubled and it performs simple harmonic motion with the same amplitude as in the first case, its maximum kinetic energy is \(K_2\). Then :

A monochromatic light is incident at a certain angle on an equilateral triangular prism and suffers minimum deviation. If the refractive index of the material of the prism is \(\sqrt{3}\), then the angle of incidence is:

In a photoelectric experiment, the wavelength of the light incident on a metal is changed from 300 nm to 400 nm. The decrease in the stopping potential is close to: ( \( \frac{hc}{e} = 1240 \) nm eV)

In a double-slit experiment, green light (5303 Å) falls on a double slit having a separation of \(19.44\ \mu\mathrm{m}\) and a width of \(4.05\ \mu\mathrm{m}\). The number of bright fringes between the first and the second diffraction minima is :

An electric field of 1000 V/m is applied to an electric dipole at angle of \( 45^\circ \). The value of electric dipole moment is \( 10^{-29} \) C.m. What is the potential energy of the electric dipole?

In the circuit shown, the potential difference between A and B is :