Which chemical must be applied to the roots to keep the leaves of a plant green?

Which compound has the lowest melting point?

If $(a+\sqrt{2} b \cos x)(a-\sqrt{2} b \cos y)=a^{2}-b^{2}$ where $a>b>0,$ then $\frac{dx}{dy}$ at $\left(\frac{\pi}{4}, \frac{\pi}{4}\right)$ is

The length of the subtangent at any point of the curve $x^m y^n = a^{m+n}$ is proportional to -

Which of the following substances is obtained from the fungus $Claviceps$ $\text{purpurea}$ (ergot)?

A $6 \, V$ cell with $0.5 \, \Omega$ internal resistance, a $10 \, V$ cell with $1 \, \Omega$ internal resistance and a $12 \, \Omega$ external resistance are connected in parallel. The current (in ampere) through the $10 \, V$ cell is