Which of the following forms a stable $+4$ oxidation state?

Despite being multicellular,its cells are not organized into tissues.

An electromagnetic wave of intensity $1400 ~W/m^2$ falls on a metal surface of area $1.5 ~m^2$ and is completely absorbed by it. Find the force exerted by the beam.

The equation of the hyperbola which passes through the point $(2,3)$ and has the asymptotes $4x+3y-7=0$ and $x-2y-1=0$ is

The circuit shown here is used to compare the emf of two cells $E_1$ and $E_2$ $(E_1 > E_2)$. The null point is at $C$ when the galvanometer is connected to $E_1$. When the galvanometer is connected to $E_2$,the null point will be

An inverted bell lying at the bottom of a lake $47.6 \, m$ deep has $50 \, cm^3$ of air trapped in it. The bell is brought to the surface of the lake. The volume of the trapped air will be ......... $cm^3$ (atmospheric pressure $= 70 \, cm$ of $Hg$ and density of $Hg = 13.6 \, g/cm^3$).