List of top Questions asked in WBJEE

The equation of the plane parallel to the planes x + 2y + 3z – 5 = 0 and x + 2y + 3z – 7 = 0 and equidistant from them is

If the wavelength of incident light changes from 400 nm to 300 nm, then the stopping potential of photoelectrons emitted from a surface becomes (approximately)

Which of the following statements is/are correct?

$\sqrt{4},\sqrt[4]{4},\sqrt[8]{4},\sqrt[16]{4},\dots \dots \dots$up to ∞ are roots of the equation

$\int \frac{a^{x/2}}{\sqrt{a^{-x}-a^x}}\mathrm{dx}$ is equal to

The coordinates of a moving point p are (2t² + 4, 4t + 6). Then  its locus will be a

If fourth term of an A.P. is zero, then $\frac{t_{25}}{t_{11}}$ is, where $t_n$ denotes the $n^{\text{th }}$ term of AP.

If in a triangle ABC, sin A, sin B, sin C are in A.P., then 

The sum of n terms of two AP's are in the ratio of $(3n+8):(7n+15)$. Find the ratio of their ${12}^{\text{th }}$ terms.

The number of real solutions of the equation |x|² + 5|x| + 4 = 0 is

The standard deviation of n observations $x_1,x_2,\dots x_n$ is 2 If $\sum _{i=1}^n{x}_i=20$ and $\sum _{i=1}^n{x}_i^2=100,$ then $n$ is equal to

If a point P is equidistant from A(1, 3), B(-3, 5) and C(5, -1), then PA is equal to

The shortest distance from the point (1, 2, -1) to the surface of the sphere x² + y² + z² = 54 is

If $\sin \theta =\frac{2t}{1+t^2}$ and $\theta$ lies in the second quadrant, then $\cos \theta$ is equal to

Evaluate the integral: ${\int }_1^2\log xdx$

The correct statement(s) about following sugars (X) and (Y) is/are:

Consider the following species $(\mathrm{I}){\mathrm{S}}_4{\mathrm{O}}_6^{2-}$$(\mathrm{II}){\mathrm{S}}_3{\mathrm{O}}_9$$(\mathrm{III}){\mathrm{S}}_2{\mathrm{O}}_5^{2-}$$(\mathrm{IV}){\mathrm{P}}_3{\mathrm{O}}_9^{3-}$Which of the above species have same number of $X-0-X$ linkages? $(X=P\text{ or }S)$

Q in the above sequence of reactions is

Blackened oil painting can be restored into original form by the action of:

Which one of the following observations is not true when a mixture of KCl, K2Cr2O7 and conc. H2SO4 is warmed carefully?

The addition of HBr to 2-pentene gives