List of top Questions asked in WBJEE

0.400 g of impure CaSO4 (Molar mass = 136) solution when treated with excess of barium chloride solution, gave 0.617 g of anhydrous BaSO4 (Molar mass = 233). The percentage of CaSO4 present in the sample is

Consider the reaction 2A + B →products, when the concentration of A alone was doubled, the half-life of the reaction did not change. When the concentration of B alone was doubled, the rate was not altered. The unit of rate constant for this reaction is

The energy of electron in 1st orbit of Hydrogen atom is –2.18 × 10^-18 Joule. The third ionisation energy of Li⁺² ion is

0.066 g of a metal was deposited when a current of 2 ampere passed for 100 seconds through an aqueous solution of its metal ion. The equivalent mass of the metal is-

Which of the following type of compound is used to increase the hardness of the silicone polymer.

The following reaction is an example of

If a particle moves in such a way that the displacement is proportional to the square of the velocity acquired, then its acceleration is

ABCD is a parallelogram. If $P$ and $Q$ are the respective midpoints of$\overrightarrow{\mathrm{BC}}$ and $\overrightarrow{\mathrm{AD}},$ then $,\overrightarrow{\mathrm{AB}}+\overrightarrow{\mathrm{DC}}$ is equal to

The minimum value of $f(x)={\sin }^{4}x+{\cos }^{4}x,0\le x\le \frac{\pi }{2}$

An integrating factor of the differential equation $x\frac{dy}{dx}+y\log x=x{e}^x{x}^{-\frac{1}{2}\log x},(x>0)$

If $\overrightarrow{A}=\hat{i}+2\overrightarrow{j}+3\hat{k},\overrightarrow{B}=-\hat{i}+2\hat{j}+\hat{k},\overrightarrow{C}=3\hat{i}+j$ and $\overrightarrow{A}+1\overrightarrow{B}$ is perpendicular to $\overrightarrow{\mathrm{C}},$ thent is equal to

The probability that in a family of 5 members, exactly 2 members have birthdays on Sunday, is

The value of $\sec [{\tan }^{-1}\left(\frac{b+a}{b-a}\right)-{\tan }^{-1}\left(\frac{a}{b}\right)]$

If A1, A2; G1, G2; and H1, H2 are two AMs, GMs and HMs between two quantities, then the value of $\frac{G_1{G}_2}{H_1{H}_2}$ is

An electron jumps from the fourth orbit to the second orbit of hydrogen atom. If Rydberg’s constant R is equal to 10⁷ m^–1, then the frequency of the emitted radiation in Hz will be

A galvanometer has 40 divisions and a sensitivity of 12 μA/div. it can be converted into a voltmeter to read 3 V by connecting-

products can be

Among the following complex compounds–${\mathrm{K}}_3[\mathrm{Fe}(\mathrm{CN}{)}_6]$$(i)$$\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]{\mathrm{Cl}}_3$(ii) ${\mathrm{K}}_2[\mathrm{Pt}(\mathrm{CN}{)}_4]$$(\mathrm{iii})$$\left[\mathrm{Zn}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]{\left({\mathrm{NO}}_3\right)}_2$$(iv)$diamagnetic complexes are –

The solubility product of silver chloride is 1.8 × 10^-10 at 298 k. The solubility of AgCl in 0.01 M KCl aqueous solution in mol dm^-3 is

The actinoids exhibit more number of oxidation states in general than the lanthanoids because

The curve represented by the equation 4x² + 16y² - 24x - 32y - 12 = 0 is

The derivative of${\tan }^{-1}\left(\frac{\sqrt{1+x^2}-1}{x}\right)$ with respect to ${\tan }^{-1}\left(\frac{2x\sqrt{1-x^2}}{1-2x^2}\right)$ at $x=0$

Consider the following reactions, ‘I’ and ‘II’:

Which of the above reactions effectively give(s) 4-methyl hex-2-yne?

In OF2, H2O and OCl2, there is sp³ hybridisation of central atom. The bond length and bond angle of OF2, H2O and OCl2 are given as:

Which of the following is the correct statement about the differences in the bond angles of the compounds given above?

A sample containing 1.0 mole of an ideal gas is expanded reversibly and isothermally to ten times its original volume in two separate experiments. The expansion is carried out at 300 K and 600 K, respectively. Choose the correct option.