The value of $\frac{\cot 54^\circ}{\tan 36^\circ} + \frac{\tan 20^\circ}{\cot 70^\circ}$ is

Which of the following is the correct electronic configuration of a neutral $Carbon$ atom in its ground state?

$A$ cricketer can throw a ball to a maximum horizontal distance of $100 \, m$. The speed with which he throws the ball is (to the nearest integer) (in $m/s$).

Kerosene is a mixture of $.........$.

Consider the following statements. Which of the following statements are correct?
$(i)$ Froth floatation technique is used to concentrate sulphide ore.
$(ii)$ Froth floatation technique is based upon differential wettability of ore and impurity in water.
$(iii)$ Red Bauxite is concentrated by Bayer’s process.
$(iv)$ Carbon is used as reducing agent during extraction of zinc from zinc blende.

If $a, b, c$ and $d \in \mathbb{R}$ such that $a^2+b^2=4$ and $c^2+d^2=2$ and if $(a+ib)^2=(c+id)^2(x+iy)$,then $x^2+y^2$ is equal to