Which of the following compounds exhibits optical isomerism?

$A$ certain vector in the $xy$-plane has an $x$-component of $4 ~m$ and a $y$-component of $10 ~m$. It is then rotated in the $xy$-plane so that its $x$-component is doubled. Then its new $y$-component is (approximately) (in $~m$)

Which of the following organisms possesses a cell wall made of peptidoglycan?

Vessels and Companion cells are characteristics of

The magnetic field due to a straight conductor of uniform cross section of radius $a$ and carrying a steady current is represented by

The mean and standard deviation of a binomial variate $X$ are $4$ and $\sqrt{3}$ respectively. Then $P(X \geq 1)$ is equal to