List of top Questions asked in JEE Main- 2020

Arrange the following labelled hydrogens in decreasing order of acidity :

Consider the reaction sequence given below:

Which of the following statements is true?

A cylindrical vessel containing a liquid is rotated about its axis so that the liquid rises at its sides as shown in the figure. The radius of vessel is 5 cm and the angular speed of rotation is \(\omega\) rad s\(^{-1}\). The difference in the height, \(h\) (in cm) of liquid at the centre of vessel and at the side will be :

Shown in the figure is rigid and uniform one meter long rod \(AB\) held in horizontal position by two strings tied to its ends and attached to the ceiling. The rod is of mass \(m\) and has another weight of mass \(2m\) hung at a distance of 75 cm from \(A\). The tension in the string at \(A\) is :

A uniform cylinder of mass \(M\) and radius \(R\) is to be pulled over a step of height \(a\) (\(a \lt R\)) by applying a force \(F\) at its centre \(O\) perpendicular to the plane through the axes of the cylinder on the edge of the step (see figure). The minimum value of \(F\) required is :

A spherical mirror is obtained as shown in the figure from a hollow glass sphere. If an object is positioned in front of the mirror, what will be the nature and magnification of the image of the object?
(Figure drawn as schematic and not to scale)

A charged particle (mass \(m\) and charge \(q\)) moves along X-axis with velocity \(V_0\). When it passes through the origin it enters a region having uniform electric field \(\vec{E}=-E\hat{j}\) which extends upto \(x=d\). Equation of path of electron in the region \(x \gt d\) is

The major product obtained from \(\mathrm{E_2}\) - elimination of 3-bromo-2-fluoropentane is

A small block starts slipping down from a point B on an inclined plane AB, which is making an angle \(\theta\) with the horizontal section BC is smooth and the remaining section CA is rough with a coefficient of friction \(\mu\). It is found that the block comes to rest as it reaches the bottom (point A) of the inclined plane. If BC = 2AC, the coefficient of friction is given by \(\mu = k\tan\theta\). The value of k is ________.

The increasing order of the following compounds towards HCN addition is :

The IUPAC name for the following compound is

Consider the following rections:

'x', 'y' and 'z' in these reactions are respectively.

The major aromatic product C in the following reaction sequence will be :

The figure that is not a direct manifestation of the quantum nature of atoms is :

The major product in the following reaction is :

In Carius method of estimation of halogen, 0.172 g of an organic compound showed presence of 0.08 g of bromine. Which of these is the correct structure of the compound?

Which one of the following graphs is not correct for ideal gas?

d = Density, P = Pressure, T = Temperature

The number of chiral carbons present in the molecule given below is _____ .

An electron gun is placed inside a long solenoid of radius R on its axis. The solenoid has n turns/length and carries a current I. The electron gun shoots an electron along the radius of the solenoid with speed v. If the electron does not hit the surface of the solenoid, maximum possible value of v is (all symbols have their standard meaning) :

A uniformly thick wheel with moment of inertia \(I\) and radius \(R\) is free to rotate about its centre of mass (see fig). A massless string is wrapped over its rim and two blocks of masses \(m_1\) and \(m_2\) (\(m_1 \gt m_2\)) are attached to the ends of the string. The system is released from rest. The angular speed of the wheel when \(m_1\) descents by a distance \(h\) is :

The current \(i\) in the network is :

An electric field \(\overrightarrow{E} = 4x\,\hat{i} - (y^2 + 1)\hat{j}\) N/C passes through the box shown in figure. The flux of the electric field through surfaces ABCD and BCGF are marked as \(\phi_I\) and \(\phi_{II}\) respectively. The difference between \((\phi_I - \phi_{II})\) is (in Nm\(^2\)/C) _______.

In a meter bridge experiment S is a standard resistance. R is a resistance wire. It is found that balancing length is \(l\) = 25 cm. If R is replaced by a wire of half length and half diameter that of R of same material, then the balancing distance \(l'\) (in cm) will now be________.

The circuit shown below is working as a 8 V dc regulated voltage source. When 12 V is used as input, the power dissipated (in mW) in each diode is; (considering both zener diodes are identical) _________.

Consider the following reactions,

The compound [P] is :