Tetrarch vascular bundles are found in .......

An expression of energy density is given by $u = \frac{\alpha}{\beta} \sin \left(\frac{\alpha x}{kt}\right)$,where $\alpha$ and $\beta$ are constants,$x$ is displacement,$k$ is the Boltzmann constant,and $t$ is the temperature. The dimensions of $\beta$ will be $-$

If $S_{n} = 1^3 + 2^3 + \ldots + n^3$ and $T_{n} = 1 + 2 + \ldots + n$,then

Which of the following pairs of transition metal ions have the same calculated values of magnetic moment?

The expression $\tan 9^{\circ}-\tan 27^{\circ}-\tan 63^{\circ}+\tan 81^{\circ}$ is equal to

Which of the following contains a coordinate covalent bond?