The kinetic energy needed to project a body of mass $m$ from the earth's surface (radius $R$) to infinity is

What percentage of the population in India is employed in the agricultural sector?

During meiosis $I$,the chromosomes start pairing at

$A$ musical instrument $P$ produces sound waves of frequency $n$ and amplitude $A_P$. Another musical instrument $Q$ produces sound waves of frequency $\frac{n}{4}$. The waves produced by $P$ and $Q$ have equal energies. If the amplitude of waves produced by $P$ is $A_P$,the amplitude of waves produced by $Q$ will be: (in $A_P$)

Which of the following is not an essential amino acid?

The synthesis of crotonaldehyde from acetaldehyde is an example of $.......$ reaction.