What is the scientific name of tea?

The electronic configurations of $Eu$ (Atomic No $63$),$Gd$ (Atomic No $64$) and $Tb$ (Atomic No $65$) are

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:

The only cations present in a slightly acidic solution are $Fe^{3+}$,$Zn^{2+}$,and $Cu^{2+}$. The reagent that,when added in excess to this solution,would identify and separate $Fe^{3+}$ in one step is

The solution of the differential equation $\frac{dy}{dx} - 2y \tan 2x = e^x \sec 2x$ is

Which of the following substances is known as $Oil$ $of$ $Wintergreen$?