The first biosphere reserve established in India for conserving the gene pool of flora and fauna and the lifestyle of tribals is

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

Aluminium vessels should not be washed with materials containing washing soda since

The number of oxygen atoms bonded to one phosphorous atom in $P_4O_6$ is

$2, 3$-dimethylhexane contains tertiary,secondary,and primary carbon atoms,respectively:

$A$ particle $A$ of mass $m$ and initial velocity $v$ collides with a particle $B$ of mass $\frac{m}{2}$ which is at rest. The collision is head-on and elastic. The ratio of de-Broglie wavelengths $\lambda_{A}$ to $\lambda_{B}$ after the collision is