$HCl$ is added to the following oxides,which one would give $H_2O_2$?

The major product of the following reaction is

If $f(t) = \int_{-t}^t \frac{e^{-|x|}}{2} dx$,then $\lim_{t \rightarrow \infty} f(t)$ is equal to:

$A$ transformer is used to light a $140 \, W, 24 \, V$ lamp from a $240 \, V \, AC$ mains. The current in the main cable is $0.7 \, A$. The efficiency of the transformer is......$\%$

Methanogens belong to $..........$.

We can define a facultative parasite as one which: