Sulphide ores of metals are usually concentrated by froth floatation process. Which one of the following sulphide ores offers an exception and is concentrated by chemical leaching?

Which of the following represents the correct order of the acidity in the given compounds?

If $A$ and $B$ are two independent events such that $P(B)=\frac{2}{7}$ and $P(A \cup B^c)=0.8$, then $P(A)$ is equal to:

An infinitely long thin straight wire has a uniform linear charge density of $\frac{1}{3} ~Cm^{-1}$. The magnitude of the electric field intensity at a point $18 ~cm$ away is (given $\varepsilon_0 = 8.85 \times 10^{-12} ~C^2 N^{-1} m^{-2}$):

Which stage is indicated by the given figure?

The degree of the differential equation $\frac{d^2y}{dx^2} + 3\left[ \frac{dy}{dx} \right]^2 = x^2 \log \left[ \frac{d^2y}{dx^2} \right]$ is