Boron hydrides are prepared by the action of dil. HCl on \({Mg_3B_2}\) .
All the B-H bonds in \(B_2H_6\) are not equal. The four terminal B-H bonds are shorter (B-H bond length = 1.19 \(\mathring A\)) than the two bridged B-H-B bonds (bond length - 1.33 \(\mathring A\)).
So, the correct option is (B): All the B-H bonds in $B_2H_6$ are equal.
Method used for separation of mixture of products (B and C) obtained in the following reaction is: 
A substance 'X' (1.5 g) dissolved in 150 g of a solvent 'Y' (molar mass = 300 g mol$^{-1}$) led to an elevation of the boiling point by 0.5 K. The relative lowering in the vapour pressure of the solvent 'Y' is $____________ \(\times 10^{-2}\). (nearest integer)
[Given : $K_{b}$ of the solvent = 5.0 K kg mol$^{-1}$]
Assume the solution to be dilute and no association or dissociation of X takes place in solution.
Inductance of a coil with \(10^4\) turns is \(10\,\text{mH}\) and it is connected to a DC source of \(10\,\text{V}\) with internal resistance \(10\,\Omega\). The energy density in the inductor when the current reaches \( \left(\frac{1}{e}\right) \) of its maximum value is \[ \alpha \pi \times \frac{1}{e^2}\ \text{J m}^{-3}. \] The value of \( \alpha \) is _________.
\[ (\mu_0 = 4\pi \times 10^{-7}\ \text{TmA}^{-1}) \]