The number of structural isomers for $C_6H_{14}$ is

Two particles of equal mass have velocities $\overrightarrow{v}_1=4 \hat{i} \text{ ms}^{-1}$ and $\overrightarrow{v}_2=4 \hat{j} \text{ ms}^{-1}$. The first particle has an acceleration $\overrightarrow{a}_1=(5 \hat{i}+5 \hat{j}) \text{ ms}^{-2}$ while the acceleration of the other particle is zero. The centre of mass of the two particles moves in a path of

The differential equation of the family $y=a e^x+b x e^x+c x^2 e^x$ of curves, where $a, b, c$ are arbitrary constants, is

Which of the following is not optically active?

Which stage is indicated by the given figure?

The major product of the following reaction is