Newman projection of Butane is given, $\mathrm{C}-2$ is rotated by $120°$ along ${\mathrm{C}}_2-{\mathrm{C}}_3,$ bond in anticlockwise direction the conformation formed is:

Which of the following is correct $\mathrm{P}.\mathrm{E}.$ diagram for propane and butane, respectively?

The Newman projection formula of $\mathrm{}$ 2, 3$\mathrm{}$ -dimethylbutane is given as

$\mathrm{}$ \mathrm{X}, \mathrm{Y},$\mathrm{}$ respectively can be:

What is the correct $\mathrm{IUPAC}$ name of following compound ?

What is the correct $\mathrm{IUPAC}$ name of following compound ?

Correct $\mathrm{IUPAC}$ name of

is :

Correct $\mathrm{IUPAC}$ name of

is :