Sodium and copper have work functions of $2.3 \ eV$ and $4.5 \ eV$ respectively. The ratio of their threshold wavelengths is nearest to:

$A$ group of atoms can function as a ligand only when

Which of the following is not correct?

For the oxidation of $0.2 \ M \ FeSO_4$ solution,$0.965 \ A$ current is passed through it for $1 \ hour$. The volume of the solution that is oxidized in $mL$ is:

$A$ uniform rope of length $L$ and mass $m_1$ hangs vertically from a rigid support. $A$ block of mass $m_2$ is attached to the free end of the rope. $A$ transverse pulse of wavelength $\lambda_1$ is produced at the lower end of the rope. The wavelength of the pulse when it reaches the top of the rope is $\lambda_2$. The ratio $\lambda_2/\lambda_1$ is

The synthesis of $ATP$ in photosynthesis and respiration is essentially an oxidation-reduction process involving the removal of energy from: