List of top Questions asked in WBJEE

If $C_{0}, C_{1}, C_{2}, \ldots, C_{n}$ denote the coefficients in the expansion of $(1+x)^{n}$, then the value of $C_{1}+2C_{2}+3C_{3}+\ldots+nC_{n}$ is

For what value of $m$, $\frac{a^{m+1}+b^{m+1}}{a^{m}+b^{m}}$ is the arithmetic mean of $�a�$ and $�b�$ ?

If $\alpha, \beta $ be the roots of $x^{2}-a(x-1)+b=0$, then the value of $\frac{1}{\alpha^{2}-a\alpha}+\frac{1}{\beta^{2}-a\beta}+\frac{2}{a+b}$ is

$A$ and $B$ are two independent events such that $P\left(A\cup B'\right)=0.8$, and $P\left(A\right)=0.3$ Then, $P(B)$ is

The equation of the tangent to the conic $x^{2}-y^{2}-8x+2y+11=0$ at $(2,1)$ is

Which one of the following formulae does not represent an organic compound?

What is the particle $X$ in the following nuclear reaction : $^{9}_{4}Be +^{4}_{2}He \to \,^{12}_{6} C +X$

The slope at any point of a curve $y = f(x )$ is given by $\frac{d y}{d x}=3x^{2}$ and it passes through $(-1 ,1 )$ The equation of the curve is

The coordinates of the foot of the perpendicular from $(0,0)$ upon the line $x + y = 2$ are

The number of electron in $2$ coulomb of charge is

Angle between $y^{2}=x$ and $x^{2}=y$ at the origin is

$1$ mole of photon, each of frequency $2500\,s^{-1},$ would have approximately a total energy of :

Which one of the following is called a carbylamine?

For any complex number $z$, the minimum value of $\left|z\right|+\left|z-1\right|$ is

An $L C R$ series circuit containing a resistance of $120 \,\Omega$ has angular resonance frequency $4 \times 10^{5} \,rad \,s ^{-1}$. At resonance the voltage across resistance and inductance are $60\, V$ and $40 \,V$ respectively. The values of $L$ and $C$ are

The distance between an object and a divergent lens is $m$ times the focal length of the lens. The linear magnification produced by the lens is

If the charge on a capacitor is increased by $2$ coulomb, the energy stored in it increases by $21\%$. The original charge on the capacitor is

The time taken for $10\%$ completion of a first order reaction is $20$ minutes. Then for $19\%$ completion the reaction will take

An organic compound made of $C, H$ and $N$ contains $20\%$ nitrogen. Its molecular weight is :

The equilibrium constant (K) of a reaction may be written as :

Which of the following will decrease the $pH$ of a $50\, ml$ solution of $0.01 \,M \,HCl$?

For the reaction $SO_{2} +\frac{1}{2} O_{2} =SO_{3,}$ if we write $K_{p}=K_{c} \left(RT\right)^{x},$ then x becomes

Trophic levels in ecosystem is formed by

By which of the following methods, new and better varieties of plants can be formed?