Which of the following products is formed when $SiF_4$ reacts with water?

Consider a $p-n$ junction as a capacitor,formed with $p$ and $n$-materials acting as thin metal electrodes and depletion layer width acting as separation between them. Basing on this,assume that an $n-p-n$ transistor is working as an amplifier in $CE$ configuration. If $C_1$ and $C_2$ are the base-emitter and collector-emitter junction capacitances,then :

If $a$ and $b$ are positive integers such that $b > a$,then $\lim _{n \rightarrow \infty} \left[ \frac{1}{na} + \frac{1}{na+1} + \frac{1}{na+2} + \ldots + \frac{1}{nb} \right] = $

$A$ weak acid $HX$ has the dissociation constant $1 \times 10^{-5} \text{ } M$. It forms a salt $NaX$ on reaction with alkali. The percentage hydrolysis of $0.1 \text{ } M$ solution of $NaX$ is ............... $\%$

$\lim _{x \rightarrow \infty}\left(\frac{x+5}{x+2}\right)^{x+3}$ equals

Which group includes microorganisms that lack a defined nucleus but contain genetic material (nucleoid)?