Tetrahalides of group $14$ elements (except that of carbon) act as:

Which of the following compounds exhibits optical isomerism?

In the circuit,if the forward voltage drop for the diode is $0.5 \, V$,the current will be........$mA$.

How many $g$ of a dibasic acid (Mol. wt. $= 200$) should be present in $100 \ ml$ of its aqueous solution to give a decinormal strength?

$\lim _{x \rightarrow 0} x^2 \sin \left(\frac{\pi}{x}\right)$ is equal to

If $\alpha$ and $\beta$ are the roots of the equation $ax^2+bx+c=0$ and the equation having roots $\frac{1-\alpha}{\alpha}$ and $\frac{1-\beta}{\beta}$ is $px^2+qx+r=0$,then $r=$