Identify the major product formed when the following compound reacts with $NBS$ ($N$-Bromosuccinimide):
$CH_3-C_6H_4-CH(CH_3)-C_6H_4-CH_2CH_3 \xrightarrow{NBS} \text{Major Product}$

$CH_3-CH(CH_3)-CH_2-CH_3 \xrightarrow{Cl_2/h\nu} N$ (number of isomers) $\xrightarrow{\text{Fractional distillation}} (F)$. Find $N$ and $F$.

Which of the following compounds is the most stable?

Which of the following has the highest knocking tendency in an internal combustion engine?

Given below are two statements $:$
Statement $(I) :$ Neopentane forms only one monosubstituted derivative.
Statement $(II) :$ Melting point of neopentane is higher than $n-$pentane.
In the light of the above statements,choose the most appropriate answer from the options given below $:$

Arrange the following in increasing order of boiling point.
$(i)$ methane,butane,propane,pentane,ethane.
$(ii)$ $n$-pentane,neo-pentane,iso-pentane.
$(iii)$ ethane,$2$-methyl propane,propane,$n$-butane.
$(iv)$ $2$-methyl pentane,$2,2$-dimethyl butane,$2,2$-dimethyl propane.