List of top Questions asked in WBJEE

If a bar magnet of magnetic moment M is kept in a uniform magnetic field B, its time period of oscillation is T. In the same magnetic field, the time period of another magnet of same dimension and same mass but of moment M/4 is,

The sum of n terms of the following series; $1^3 + 3^3 + 5^3 + 7^3 + ....$ is

The correct IUPAC name of $H_{3}C-C\left(CH_{3}\right)_{2} -CH =CH_{2}$ is

Which structure for $XeO_{3} \, and XeF_{4}$ are consistent with the VSEPR model?

Which property that polyacetylene exhibits is unusual for an organic polymer?

Which one of the following does not produce $O_{2}$ as the only gaseous product on heating?

Among the following groupings, which one represents the set of iso-electronic species?

Assign the Bravais lattice type of the following unit cell structure.

An n-p-n transistor of current gain 80 in common emitter mode gives emitter current equal to 8.1 mA. The base current is

The number of values of $k$ for which the equation $x^2 - 3x + k = 0$ has two distinct roots lying in the interval $(0, 1)$ are

The points of the ellipse $16x^2 + 9y^2 = 400$ at which the ordinate decreases at the same rate at which the abscissa increases is/are given by

A zener diode has break down voltage of 5.0 V. The resistance required to allow a current of 100 mA through the zener in reverse bias when connected to a battery of emf 12 V is

The number of points at which the function $f \left(x\right)=max \left\{a-x, a+x, b\right\}, -\infty, 0 < a < b$ cannot be differentiable

If $\frac{1}{^{5}C_{r}}+\frac{1}{^{6}C_{r}} =\frac{1}{^{4}C_{r}}$, then the value of $r$ equals to

The spin-only magnetic moment of $\left[crF_{6}\right]^{4-}$ (atomic number of Cr is 24) is

Which reaction is not appropriate for the synthesis of the following?

If $[x]$ denotes the greatest integer less than or equal to $x$, then the value of the integral $\int\limits^{{2}}_{{0}}x^2 [x] dx$

If the matrix $A=\begin{pmatrix}2&0&0\\ 0&2&0\\ 2&0&2\end{pmatrix},$ then $A^{n}=\begin{pmatrix}a&0&0\\ 0&a&0\\ b&0&a\end{pmatrix}, n\,\in\,N$ where

For non-zero vectors $\vec{a} $ and $\vec{b} $ if $\left|\vec{a}+\vec{b}\right|

The letters of the word COCHIN are permuted and all permutation are arranged in an alphabetical order as in an English dictionary. The number of words that appear before the word COCHIN is

The magnetic field intensity at the centre of cubical cage of identical wires of length ?a? due to a current I flowing as shown in the fiigure is

75% of a first order reaction was completed in 32 min. When would 50% of the reaction completed?

The emf of a Daniel cell at 298 K is $E_{1}.\qquad$The cell is $Zn | ZnSO_{4} \left(0.01M\right)|| CuSO_{4} \left(1M\right) | CU$ When the concentration of $ZnSO_{4}$ is changed to 1M and that of $CuSO_{4}$ to 0.01M, the emf changes to E2.The relationship between $E_{1} and E_{2}$ will be

Of the following atoms, which one has the highest n/p ratio?

General solution of $y \frac{dy}{dx}+by^{2}=a\,cos\,x, 0 < x< 1$ is