The element californium belongs to the family

In the adjoining circuit,the battery $E_1$ has an emf of $12 \, V$ and zero internal resistance,while the battery $E_2$ has an emf of $2 \, V$. If the galvanometer $G$ reads zero,then the value of the resistance $X$ (in $\Omega$) is

The phosphate of a metal has the formula $MHPO_4$. The formula of its chloride would be

$A$ mixture of plane polarised and unpolarised light falls normally on a polarizing sheet. On rotating the polarizing sheet about the direction of the incident beam,the transmitted intensity varies by a factor of $4$. Find the ratio of the intensities $I_P$ and $I_0$,respectively of the polarized and unpolarized components in the incident beam.

The value of $x$,where $x>0$ and $\tan \left(\sec ^{-1}\left(\frac{1}{x}\right)\right)=\sin \left(\tan ^{-1} 2\right)$ is

Which kingdom consists of organisms that are multicellular,aquatic or terrestrial,heterotrophic,and eukaryotic?