$23 \ g$ of $Na$ metal reacts with ethanol to produce which of the following?

$A$ transverse harmonic wave on a string is described by $y = 3 \sin(36t + 0.018x + \frac{\pi}{4})$,where $x$ and $y$ are in $cm$ and $t$ is in $s$. The least distance between two successive crests in the wave is .... $m$. (in $.5$)

In the following combinations of logic gates,the outputs of $A, B$ and $C$ are respectively:

In which of the following molecules is the $N$ atom not $sp^2$ hybridized?

Which of the following structures corresponds to the product expected when an excess of $C_6H_6$ reacts with $CH_2Cl_2$ in the presence of anhydrous $AlCl_3$?

In the circuit shown in the figure,$C = 6\,\mu F$. The charge stored in the capacitor of capacity $C$ is..........$\mu C$.