Which important greenhouse gas,other than methane,is produced from agricultural fields?

$A$ nucleus of an element $_{84}X^{202}$ emits an $\alpha$-particle first,a $\beta$-particle next,and then a gamma photon. The final nucleus formed has an atomic number:

Bowman's glands are located in the .......

Three rings each of mass $M$ and radius $R$ are arranged as shown in the figure. The moment of inertia of the system about the axis $YY'$ is:

$C_2H_6 \stackrel{450^{\circ}C}{\longrightarrow} C_2H_4 + H_2$. The above reaction is called:

If the volume of a parallelepiped with coterminous edges $4 \hat{i} + 5 \hat{j} + \hat{k}$,$-\hat{j} + \hat{k}$,and $3 \hat{i} + 9 \hat{j} + p \hat{k}$ is $34$ cubic units,then $p$ is equal to: