Which of the following alcohols reacts most rapidly with alkali metals?

If $\alpha, \beta, \gamma$ are the roots of the equation $x^3-6x^2+11x+6=0$,then $\Sigma \alpha^2 \beta+\Sigma \alpha \beta^2$ is equal to :

$A$ thin converging lens of focal length $f=25 \ cm$ forms the image of an object on a screen placed at a distance of $75 \ cm$ from the lens. The screen is moved closer to the lens by a distance of $25 \ cm$. The distance through which the object has to be shifted,so that its image on the screen is sharp again,is (in $cm$)

An aluminium ring $B$ faces an electromagnet $A$. The current $I$ through $A$ can be altered. Which of the following statements is correct?

In a series $LCR$ circuit,what will be the nature of the circuit for frequencies higher than the resonance frequency?

The frequency for which a $5\,\mu F$ capacitor has a reactance of $\frac{1}{1000}\,\Omega$ is given by