What is the primary objective of plant breeding?

Which set of elements forms stable,covalently bonded hydrogen-bonded hydrides?

$A$ charge of $1 \mu C$ is divided into two parts such that their charges are in the ratio of $2: 3$. These two charges are kept at a distance $1 \ m$ apart in vacuum. Then,the electric force between them (in $N$) is

In the following compounds,the order of acidity is:
$(I)$ Phenol
$(II)$ $p$-Cresol
$(III)$ $m$-Nitrophenol
$(IV)$ $p$-Nitrophenol

Two simple harmonic motions of angular frequency $100 \ rad \ s^{-1}$ and $1000 \ rad \ s^{-1}$ have the same displacement amplitude. The ratio of their maximum acceleration is

Let $f: R \rightarrow R$ be a function such that $f(x)=x^3+x^2 f^{\prime}(1)+x f^{\prime \prime}(2)+6, x \in R$,then $f(2)$ equals