List of top Questions asked in JEE Main

An ideal gas undergoes isothermal compression from 5 \(\mathrm{m^3}\) to 1 \(\mathrm{m^3}\) against a constant external pressure of 4 \(\mathrm{N\,m^{-2}}\). Heat released in this process is used to increase the temperature of 1 mole of Al. If molar heat capacity of Al is 24 \(\mathrm{J\,mol^{-1}\,K^{-1}}\), the temperature of Al increases by :
The major product of the following reaction is :
The pair that contains two P - H bonds in each of the oxoacids is
In the reaction of oxalate with permanganate in acidic medium, the number of electrons involved in producing one molecule of \(\mathrm{CO_2}\) is :
The correct match between item 'I' and item 'II' is :
Item 'I' (compound)Item 'II' (reagent)
(A) Lysine(P) 1-naphthol
(B) Furfural(Q) ninhydrin
(C) Benzylalcohol(R) KMnO4
(D) Styrene(S) Ceric ammonium nitrate
The major product obtained in the following reaction is :
For an elementary chemical reaction, \(\mathrm{A_2} \underset{K_{-1}}{\overset{K_1}{\rightleftharpoons}} 2\mathrm{A}\), the expression for \(\frac{d[A]}{dt}\) is
The major product of the following reaction
Which of the following tests cannot be used for identifying amino acids?
A reaction of cobalt (III) chloride and ethylenediamine in a 1 : 2 mole ratio generates two isomeric products A (violet coloured) and B (green coloured). A can show optical activity, but B is optically inactive. What type of isomers does A and B represcent?
The ground state energy of hydrogen atom is \(-13.6\) eV. The energy of second excited state of \(\mathrm{He^{+}}\) ion in eV is :
The modulation frequency of an AM radio station is 250 kHz, which is 10% of the carrier wave. If another AM station approaches you for license what broadcast frequency will you allot ?
Elevation in the boiling point for 1 molar solution of glucose is 2 K. The depression in the freezing point for 2 molal solution of glucose in the same solvent is 2 K. The relation between \(K_b\) and \(K_f\) is
An unknown metal of mass 192 g heated to a temperature of \(100^\circ\mathrm{C}\) was immersed into a brass calorimeter of mass 128 g containing 240 g of water at a temperature of \(8.4^\circ\mathrm{C}\). Calculate the specific heat of the unknown metal if water temperature stabilizes at \(21.5^\circ\mathrm{C}\). (Specific heat of brass is 394 J kg-1 K-1)
The difference in the number of unpaired electrons of a metal ion in its high spin and low-spin octahedral complexes is two. The metal ion is :
What will be the major product in the following mononitration reaction ?
A metal plate of area \(1\times10^{-4}\ \mathrm{m^2}\) is illuminated by a radiation of intensity 16 mW/m2. The work function of the metal is 5 eV. The energy of the incident photons is 10 eV and only 10% of it produces photo electrons. The number of emitted photoelectrons per second and their maximum energy, respectively, will be
A parallel plate capacitor having capacitance 12 pF is charged by a battery to a potential difference of 10 V between its plates. The charging battery is now disconnected and a porcelain slab of dielectric constant 6.5 is slipped between the plates. The work done by the capacitor on the slab is :
Two kg of a monoatomic gas is at a pressure of \(4\times10^4\ \mathrm{N/m^2}\). The density of the gas is 8 kg/m3. What is the order of energy of the gas due to its thermal motion ?
A hoop and a solid cylinder of same mass and radius are made of a permanent magnetic material with their magnetic moment parallel to their respective axes. But the magnetic moment of hoop is twice of solid cylinder. They are placed in a uniform magnetic field in such a manner that their magnetic moments make a small angle with the field. If the oscillation periods of hoop and cylinder are Th and Tc respectively, then -
A current of 2 mA was passed through an unknown resistor which dissipated a power of 4.4 W. Dissipated power when an ideal power supply of 11 V is connected across it is -
The electric field of a plane polarized electromagnetic wave in free space at time t = 0 is given by an expression
\(\vec E(x,y)=10\hat j\cos[(6x+8z)]\).
The magnetic field \(\vec B(x,z,t)\) is given by - (c is the velocity of light)
Four equal point charges Q each are placed in the xy plane at (0, 2), (4, 2), (4, -2) and (0, -2). The work required to put a fifth charge Q at the origin of the coordinate system will be -
Charges -q and +q located at A and B, respectively, constitute an electric dipole. Distance AB = 2a, O is the mid point of the dipole and OP is perpendicular to AB. A charge Q is placed at P where OP = y and y >> 2a. The charge Q experiences an electrostatic force F. If Q is now moved along the equatorial line to P' such that OP' = \(\left(\frac y3\right)\), the force on Q will be close to - \(\left(\frac y3\gg2a\right)\)
A particle starts from the origin at time t = 0 and moves along the positive x-axis. The graph of velocity with respect to time is shown in figure. What is the position of the particle at time t = 5s ?