The organization of living organisms starts with which level?

If there were no gravity,which of the following will not be there for a fluid?

$A$ certain metal is used in the preparation of antacids. This metal accidentally catches fire and cannot be extinguished using $CO_2$. Which metal is this?

$Ni$ anode is used in the electrolytic extraction of

The figure shows the experimentally measured $B$ vs $H$ variation in a ferromagnetic material. The values of retentivity,coercivity,and saturation magnetic field of the material are respectively:

If the harmonic mean between the roots of $(5+\sqrt{2}) x^2-b x+(8+2 \sqrt{5})=0$ is $4$,then the value of $b$ is