The equation $4x^2 - 24xy + 11y^2 = 0$ represents

$A$ random variable $X$ takes the values $0, 1$ and $2$. If $P(X=1)=P(X=2)$ and $P(X=0)=0.4$,then the mean of the random variable $X$ is

$A$ block of mass $M_1$ is hung by a light spring of force constant $k$ from the top bar of a reverse $U$-frame of mass $M_2$ resting on the floor. The block is pulled down from its equilibrium position by a distance $x$ and then released. The minimum value of $x$ such that the reverse $U$-frame will leave the floor momentarily is:

Dimensions of a block are $1\,cm \times 1\,cm \times 100\,cm$. If the specific resistance of its material is $3 \times 10^{-7}\, \Omega \cdot m$, then the resistance between the opposite rectangular faces (the square ends) is:

Which of the following is a square planar complex ion?

If $y=\tan ^{-1}\left(\frac{\sqrt{1+a^2 x^2}-1}{a x}\right)$,then $\left(1+a^2 x^2\right) y^{\prime \prime}+2 a^2 x y^{\prime}$ is equal to