Which of the following is $NOT$ included in the class of Bryophyta as classified by Rothmaler?

When an orange solution containing $Cr_2O_7^{2-}$ ions is treated with an alkali,a yellow solution is formed,and when $H^{+}$ ions are added to the yellow solution,an orange solution is obtained. Explain why this happens.

In which of the following compounds is the ratio of the size of the anion to the size of the cation the smallest?

Select the correct statement regarding the following change:
$NO_2^+ \to NO_2 \to NO_2^-$

The binding energy per nucleon of ${O^{16}}$ is $7.97 \, MeV$ and that of ${O^{17}}$ is $7.75 \, MeV$. The energy (in $MeV$) required to remove a neutron from ${O^{17}}$ is

$A$ uniform rope of mass $0.1 ~kg$ and length $2.45 ~m$ hangs from a rigid support. The time taken by the transverse wave formed in the rope to travel through the full length of the rope is (Assume $g=9.8 ~m/s^2$) (in $~s$)