The hybridisation of $S$ in $SF_{4}$ is

What is the decreasing order of carbon-carbon single bond length in the following compounds?
$(I) CH_2 = CH - C \equiv CH$
$(II) CH \equiv C - C \equiv CH$
$(III) CH_3 - CH = CH_2$
$(IV) CH_2 = CH - CH = CH_2$

The hybridization of $P$ exhibited in $PF_{5}$ is $sp^{x}d^{y}$. The value of $y$ is $...$

The central atom in a molecule is in $sp^2$ hybrid state. The shape of the molecule will be

As the $s$-character of the hybrid orbital decreases,the bond angle ...........

The compounds with $sp^2$ hybridized central atom among the following are:
$(A)$ $H_2CO_3$
$(B)$ $SiF_4$
$(C)$ $BF_3$
$(D)$ $HClO_2$