Which of the following acids is a vitamin?

To what temperature should the hydrogen at $327^{\circ}C$ be cooled at constant pressure,so that the root mean square velocity of its molecules becomes half of its previous value? (in $^{\circ}C$)

If $g(x) = \int_0^x \cos^4 t \, dt$,then $g(x + \pi)$ equals

Which one of the following is an example of cleistogamy?

$A$ vessel contains $1 \, mole$ of $O_2$ gas (molar mass $32$) at a temperature $T$. The pressure of the gas is $P$. An identical vessel containing one mole of $He$ gas (molar mass $4$) at a temperature $2T$ has a pressure of:

For a normal eye,the cornea of the eye provides a converging power of $40 \ D$ and the least converging power of the eye lens behind the cornea is $20 \ D$. Using this information,the distance between the retina and the cornea-eye lens can be estimated to be ......... $cm$.