Select the correct statement:

$A$ satellite is revolving very close to a planet of density $\rho$. The period of revolution of the satellite is

$A$ sodium atom is in one of the states labeled 'Lowest excited levels'. It remains in that state for an average time of $10^{-8} \ s$,before it makes a transition back to a ground state. What is the uncertainty in energy of that excited state?

In Young's double slit experiment,the seventh maximum with wavelength ${\lambda _1}$ is at a distance $d_1$ from the central maxima,and the same maximum with wavelength ${\lambda _2}$ is at a distance $d_2$. Then the ratio $d_1/d_2$ is:

Which of the following representations correctly explains the function of a mitochondrion?

The quantum number which explains the line spectra observed as doublets in the case of hydrogen and alkali metals and doublets and triplets in the case of alkaline earth metals is