What is the advantage of pollen culture?

Heating phthalic anhydride and concentrated sulfuric acid with which of the following yields phenolphthalein?

$A$ conducting rod of length $L$ rotates with angular speed $\omega$ in a uniform magnetic field of induction $B$ which is perpendicular to its motion. The induced emf developed between the two ends of the rod is

In a unilocular ovary with a single ovule,the placentation is

Two closed organ pipes of length $100\,cm$ and $101\,cm$ long give $16$ beats in $20\,sec$ when each pipe is sounded in fundamental mode. Calculate the velocity of sound in $m/s$.

Crystalline sodium chloride is an insulator of electricity because $......$