List of top Questions asked in KCET, WBJEE

A bar magnet has a magnetic moment of $200\, A \,m^2$. The magnet is suspended in a magnetic field of $0.30\, N\, A^{-1}\, m^{-1}$. The torque required to rotate the magnet from its equilibrium position through an angle of $30^{\circ}$, will be

A bullet of mass $m$ travelling with a speed $v$ hits a block of mass $M$ initially at rest and gets embedded in it. The combined system is free to move and there is no other force acting on the system. The heat generated in the process will be

Tautomerism is exhibited by

The ionization energy of the hydrogen atom is $13.6\, eV$. The potential energy of the electron in $n = 2$ state of hydrogen atom is

Amongst $\left[NiCl_{4}\right]^{2-}, \left[Ni\left(H_{2}O\right)_{6}\right]^{2+},\left[Ni\left(PPh_{3}\right)_{2}Cl_{2}\right], \left[Ni\left(CO\right)_{4}\right]$ and $\left[Ni\left(CN\right)_{4}\right]^{2-}$. the paramagnetic species are

Let $P = \begin{pmatrix}cos \frac{\pi}{4}&-sin \frac{\pi}{4}\\ sin \frac{\pi}{4}&cos \frac{\pi}{4}\end{pmatrix}$ and $X = \begin{pmatrix}\frac{1}{\sqrt{2}}\\ \frac{1}{\sqrt{2}}\end{pmatrix}$. Then $P^{3}X$ is equal to

A travelling acoustic wave of frequency $500\, Hz$ is moving along the positive $x$-direction with a velocity of $300 \,ms^{-1}$. The phase difference between two points $x_1$ and $x_2$ is 60$^{\circ}$. Then the minimum separation between the two pints is

In $SOCl_2$, the $Cl-S-Cl$ and $Cl-S-O$ bond angles are

Pressure-volume $(PV)$ work done by an ideal gaseous system at constant volume is (where $E$ is internal energy of the system

The standard Gibbs free energy change $(\Delta G^\circ)$ at 25$^{\circ}$C for the dissociation of $N_2O_4(g)$ to $NO_2(g)$ is (given, equilibrium constant = $0.15, R = 8.314 \, J/K/mol)$

The best method for preparation of $Me_3CCN$ is

In basic medium the amount of $Ni^{2+}$ in a solution can be estimated with the dimethylglyoxime reagent. The correct statement(s) about the reaction and the product is(are)

$2$-Methylpropane on monochlorination under photochemical condition give

If $\sin x- \sin y = \frac {1}{2}$ and $\cos x- \cos y = 1$, then $ \tan(x + y) $ is equal to

Choose the right one which denotes genetic diversity.

The trachea terminates into

Which of the following tissue is not a component of a complex tissues ?

If the determinant of the adjoint of a (real) matrix of order $3$ is $25$, then the determinant of the inverse of the matrix is

Four small objects each of mass m are fixed at the corners of a rectangular wire-frame of negligible mass and of sides $a$ and $b (a > b)$. If the wire frame is now rotated about an axis passing along the side of length b, then the moment of inertia of the system for this axis of rotation is

If the area of the auxiliary circle of the ellipse $\frac {x^2}{a^2}+\frac {y^2}{b^2}=1 (a >\, b)$ is twice the area of the ellipse, then the eccentricity of the ellipse is

Which one of the following gives amine on heating with amide ?

Which of the following gases has the highest value of $rms$ velocity at $298\, K$?

The mass of $112 \, cm^3$ of $NH_3$ gas at $STP$ is

The ionisation energy of an electron in the ground state of helium atom is $24.6\, eV$. The energy required to remove both the electron is

For a transformer, the turns ratio is $3$ and its efficiency is $0.75$. The current flowing in the primary coil is $2\,A$ and the voltage applied to it is $100\, V$. Then the voltage and the current flowing in the secondary coil are _________ respectively.