Ethers,when dissolved in cold concentrated sulphuric acid,form:

In the Victor-Meyer's test,the colours given by $1^o$,$2^o$ and $3^o$ alcohols are respectively:

(in $\%$)

The total number of valence electrons in $4.2 \, g$ of $N_3^-$ ion is ......... $N_A$. ($N_A$ = Avogadro number)

$A$ closely wound coil of $100$ turns and area of cross-section $1 \; cm^2$ has a coefficient of self-induction $1 \; mH$. The magnetic induction in the centre of the core of the coil when a current of $2 \; A$ flows in it will be (in $Wb/m^2$):

An $X$-ray tube produces a continuous spectrum of radiation with its shortest wavelength of $45 \times 10^{-2} \text{ \AA}$. The maximum energy of a photon in the radiation in $eV$ is $(h = 6.62 \times 10^{-34} \text{ J-s}, c = 3 \times 10^8 \text{ m/s})$. (in $27,500$)