List of top Questions asked in JEE Main

The work function of sodium metal is \(4.41 \times 10^{-19}\) J. If photons of wavelength 300 nm are incident on the metal, the kinetic energy of the ejected electrons will be (h = \(6.63 \times 10^{-34}\) J s; c = \(3 \times 10^{8}\) m/s) ________ \(\times 10^{-21}\) J.

The molecular geometry of \(\mathrm{SF_6}\) is octahedral. What is the geometry of \(\mathrm{SF_4}\) (including lone pair(s) of electrons, if any)?

The results given in the below table were obtained during kinetic studies of the following reaction
\(2A + B \to C + D\)

Experiment	[A]/mol L-1	[B]/mol L-1	Initial rate/mol L-1 min-1
I	0.1	0.1	\(6.00 \times 10^{-3}\)
II	0.1	0.2	\(2.40 \times 10^{-2}\)
III	0.2	0.1	\(1.20 \times 10^{-2}\)
IV	X	0.2	\(7.20 \times 10^{-2}\)
V	0.3	Y	\(2.88 \times 10^{-1}\)

X and Y in the given table are respectively :

Three elements X, Y and Z are in the 3^rd period of the periodic table. The oxides of X, Y and Z, respectively, are basic, amphoteric and acidic. The correct order of the atomic numbers of X, Y and Z is :

If you spill a chemical toilet cleaning liquid on your hand, your first aid would be

The number of subshells associated with \(n = 4\) and \(m = -2\) quantum numbers is

Match the type of interaction in column A with the distance dependence of their interaction energy in column B

A	B
(i) ion-ion	(a) \(\frac{1}{r}\)
(ii) dipole-dipole	(b) \(\frac{1}{r^2}\)
(iii) London dispersion	(c) \(\frac{1}{r^3}\)
	(d) \(\frac{1}{r^6}\)

The size of a raw mango shrinks to a much smaller size when kept in a concentrated salt solution. Which one of the following processes can explain this?

The one that is not expected to show isomerism is :

A light ray enters a solid glass sphere of refractive index \(\mu = \sqrt{3}\) at an angle of incidence \(60^\circ\). The ray is both reflected and refracted at the farther surface of the sphere. The angle (in degrees) between the reflected and refracted rays at this surface is ________.

A heat engine is involved with exchange of heat of 1915 J, \(-40\) J, \(+125\) J and \(-Q\) J, during one cycle achieving an efficiency of 50.0%. The value of \(Q\) is

A capillary tube made of glass of radius 0.15 mm is dipped vertically in a beaker filled with methylene iodide (surface tension = 0.05 Nm^-1, density = 667 kg m^-3) which rises to height \(h\) in the tube. It is observed that the two tangents drawn from liquid-glass interfaces (from opp. sides of the capillary) make an angle of 60^o with one another. Then \(h\) is close to (\(g = 10\ \mathrm{ms^{-2}}\))

In a hydrogen atom the electron makes a transition from \((n+1)^{th}\) level to the \(n^{th}\) level. If \(n \gg 1\), the frequency of radiation emitted is proportional to :

An inductance coil has a reactance of 100 \(\Omega\). When an AC signal of frequency 1000 Hz is applied to the coil, the applied voltage leads the current by 45^o. The self-inductance of the coil is

In a Young's double slit experiment, 16 fringes are observed in a certain segment of the screen when light of a wavelength 700 nm is used. If the wavelength of light is changed to 400 nm, the number of fringes observed in the same segment of the screen would be

When the temperature of a metal wire is increased from \(0^{\circ}\mathrm{C}\) to \(10^{\circ}\mathrm{C}\), its length increases by \(0.02\%\). The percentage change in its mass density will be closest to :

A \(10\ \mu\mathrm{F}\) capacitor is fully charged to a potential difference of 50 V. After removing the source voltage it is connected to an uncharged capacitor in parallel. Now the potential difference across them becomes 20 V. The capacitance of the second capacitor is :

An ideal gas in a closed container is slowly heated. As its temperature increases, which of the following statements are true?
(A) the mean free path of the molecules decreases.
(B) the mean collision time between the molecules decreases.
(C) the mean free path remains unchanged.
(D) the mean collision time remains unchanged.

The height 'h' at which the weight of a body will be the same as that at the same depth 'h' from the surface of the earth is (Radius of the earth is R and effect of the rotation of the earth is neglected)

If the variance of the terms in an increasing A.P.,
\(b_1, b_2, b_3, \ldots, b_{11}\) is 90, then the common difference of this A.P. is _______.

If \(y=\displaystyle\sum_{k=1}^{6} k\cos^{-1}\left\{\frac{3}{5}\cos kx-\frac{4}{5}\sin kx\right\}\), then \(\frac{dy}{dx}\) at \(x=0\) is _______.

Let \([t]\) denote the greatest integer less than or equal to \(t\). Then the value of
\(\displaystyle\int_{1}^{2}\left|2x-[3x]\right|dx\) is _______.

The equation of the normal to the curve
\(y = (1+x)^{2y} + \cos^{2}(\sin^{-1}x)\) at \(x = 0\) is :

For a positive integer \(n\),
\(\left(1+\frac{1}{x}\right)^{n}\) is expanded
in increasing powers of \(x\). If three consecutive
coefficients in this expansion are in the ratio,
\(2 : 5 : 12\), then \(n\) is equal to _______.

Let the position vectors of points \(A\) and \(B\) be \(\hat{i}+\hat{j}+\hat{k}\) and \(2\hat{i}+\hat{j}+3\hat{k}\), respectively. A point \(P\) divides the line segment \(AB\) internally in the ratio \(\lambda : 1\) (\(\lambda \gt 0\)). If \(O\) is the origin and
\(\overrightarrow{OB}\cdot\overrightarrow{OP}-3\left|\overrightarrow{OA}\times\overrightarrow{OP}\right|^{2}=6\), then \(\lambda\) is equal to _______.