Which plant is useful as green manure?

Which one of the following is mainly responsible for the depletion of the ozone layer?

The most general value of $\theta$ which satisfies both the equations $\tan \theta = -1$ and $\cos \theta = \frac{1}{\sqrt{2}}$ is

From which plant were haploid plants first obtained through anther culture?

$A$ glass convex lens $(\mu_g = 1.5)$ has a focal length of $8\,cm$ when placed in air. What would be the focal length of the lens when it is immersed in water $(\mu_w = 1.33)$ (in $,cm$)?

In the Bohr series of lines of the hydrogen spectrum,the third line from the red end corresponds to which one of the following inter-orbit transitions in an atom of hydrogen?