Which of the following substances is obtained from the fungus $Claviceps$ $\text{purpurea}$ (ergot)?

In the reaction,the major product formed is:

Which of the following biomolecules acts as specific catalysts in biological reactions?

The maximum number of possible interference maxima for slit-separation equal to twice the wavelength in Young's double-slit experiment is:

$A$ thin converging lens of focal length $f=25 \ cm$ forms the image of an object on a screen placed at a distance of $75 \ cm$ from the lens. The screen is moved closer to the lens by a distance of $25 \ cm$. The distance through which the object has to be shifted,so that its image on the screen is sharp again,is (in $cm$)

What is obtained when one mole of calcium phosphide is reacted with excess water?