Foetal ejection reflex in human female is induced by

The energy liberated on complete fission of $1\, kg$ of $_{92}U^{235}$ is (Assume $200\, MeV$ energy is liberated on fission of $1$ nucleus).

Due to the Doppler effect,the shift in wavelength observed is $0.1 \ \mathring{A}$ for a star producing a wavelength of $6000 \ \mathring{A}$. The velocity of recession of the star will be ...... $km/s$.

Sodium metal crystallizes in a body-centred cubic $(bcc)$ lattice with a unit cell edge of $4.29 \ \mathring{A}$. The radius of the sodium atom is approximately: .............. $\mathring{A}$

Which element is estimated by the Carius method?

$A$ thin hollow sphere of mass $m$ is completely filled with a liquid of mass $m$. When the sphere rolls with a velocity $v$,the kinetic energy of the system is (neglect friction).