Aniline reacts with acetaldehyde to form

Along the $x$-axis,three charges $\frac{q}{2}, -q$ and $\frac{q}{2}$ are placed at $x=0, x=a$ and $x=2a$ respectively. The resultant electric potential at a point $P$ located at a distance $r$ from the charge $-q$ (where $r > a$) is ($\varepsilon_0$ is the permittivity of free space):

An inverted bell lying at the bottom of a lake $47.6 \, m$ deep has $50 \, cm^3$ of air trapped in it. The bell is brought to the surface of the lake. The volume of the trapped air will be ......... $cm^3$ (atmospheric pressure $= 70 \, cm$ of $Hg$ and density of $Hg = 13.6 \, g/cm^3$).

The following reaction is an example of a ....... reaction. $CH_2Br-CH_2Br + 2KOH(alc.) \xrightarrow{\Delta} CH \equiv CH + 2KBr + 2H_2O$

If $\hat{i}+2 \hat{j}+3 \hat{k}$ and $3 \hat{i}+2 \hat{j}+\hat{k}$ are sides of a parallelogram,then a unit vector parallel to one of the diagonals of the parallelogram is

The acute angle between the line $\vec{r}=(\hat{i}+2\hat{j}+\hat{k})+\lambda(\hat{i}+\hat{j}+\hat{k})$ and the plane $\vec{r} \cdot(2\hat{i}+\hat{j}+\hat{k})=5$ is