List of top Questions asked in JEE Main

As an electron makes a transition from an excited state to the ground state of a hydrogen- like atom/ion

A long cylindrical shell carries positive surface charge $\sigma$ in the upper half and negative surface charge $-\sigma$ in the lower half. The electric field lines around the cylinder will look like figure given in: (figures are schematic and not drawn to scale)

A thin disc of radius $b\, = \,2a$ has a concentric hole of radius '$a$' in it (see figure). It carries uniform surface charge '$\sigma$' on it. If the electric field on its axis at height '$h$' $(h < < a)$ from its centre is given as '$Ch$' then value of '$C$' is :

Higher order $( > 3 )$ reactions are rare due to

Which of the following compounds is not colored yellow?

The area (in s units) of the quadrilateral formed by the tangents at the end points of the latera recta to the ellipse $\frac{x^{2}}{9}+\frac{y^{2}}{5}=1$, is:

The correct order of thermal stability of hydroxides is :

Photochemical smog consists of excessive amount of $X$, in addition to aldehydes, ketones, peroxyacetyl nitrile $(PAN)$, and so forth. $X$ is :

Which polymer is used in the manufacture of paints and lacquers?

A short bar magnet is placed in the magnetic meridian of the earth with north pole pointing north. Neutral points are found at a distance of $30 \,cm$ from the magnet on the East - West line, drawn through the middle point of the magnet. The magnetic moment of the magnet in $Am^2$ is close to : (Given $\frac{\mu_{0}}{4\pi}=10^{-7}$ in SI units and $B_H$ = Horizontal component of earth's magnetic field = $3.6 \times 10^{-5}$ Tesla.)

Which among the following is the most reactive?

The value of $\int \limits \frac {dx}{x^2(x^4+1)^{3/4}}$ is

Calamine is an ore of :

Assuming human pupil to have a radius of $0.25\, cm$ and a comfortable viewing distance of $25\, cm$, the minimum separation between two objects that human eye can resolve at $500\, nm$ wavelength is

In the context of the Hall-Heroult process for the extraction of $Al$, which of the following statements is false?

If $f\left(x\right) = 2 \tan^{-1} x + \sin^{-1} \left(\frac{2x}{1+x^{2}}\right), x > 1$, then $f(t)$ is equal to :

Which of the following compounds is not an antacid?

Match the catalysts to the correct processes :

If the capacitance of a nanocapacitor is measured in terms of a unit $'u'$ made by combining the electronic charge $V$, Bohr radius $'a_0'$, Planck's constant $'h'$ and speed of light $'c'$ then :

An $LCR$ circuit is equivalent to a damped pendulum. In an $LCR$ circuit the capacitor is charged to $Q _{0}$ and then connected to the $L$ and R as shown below :

R If a student plots graphs of the square of maximum charge $\left( Q _{\max }^{2}\right)$ on the capacitor with time $(t) $ for two different values $L_{1}$ and $L_{2}$ $\left(L_{1}>L_{2}\right)$ of $L$ then which of the following represents this graph correctly ? (Plots are shematic and not drawn to scale)

On a hot summer night, the refractive index of air is smallest near the ground and increases with height from the ground. When a light beam is directed horizontally, the Huygens principle leads us to conclude that as it travels, the light beam

Permanent hardness in water cannot be cured by :

Which one of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy?

Which physical property of dihydrogen is wrong ?

Addition of phosphate fertilisers to water bodies causes :