The meristematic tissue responsible for the increase in the girth of a tree trunk is:

$A$ storehouse of collected plant specimens that are dried,pressed,and preserved on sheets is known as .........

Two objects of masses $200 \text{ g}$ and $500 \text{ g}$ possess velocities $10 \hat{i} \text{ m/s}$ and $(3 \hat{i} + 5 \hat{j}) \text{ m/s}$ respectively. The velocity of their centre of mass in $\text{m/s}$ is:

Two uniform strings $A$ and $B$ made of steel are made to vibrate under the same tension. If the first overtone of $A$ is equal to the second overtone of $B$ and if the radius of $A$ is twice that of $B$,the ratio of the lengths of the strings is :

Parthenocarpic fruit is

The $IUPAC$ name for the complex $[Co(NO_2)(NH_3)_5]Cl_2$ is: