Which one of the following cannot form an amphoteric oxide?

Drops of liquid of density $d$ are floating half immersed in a liquid of density $\rho$. If the surface tension of the liquid is $T$,then the radius of the drop is

Two seconds after projection,a projectile is travelling in a direction inclined at $30^o$ to the horizontal. After one more second,it is travelling horizontally. What is the magnitude and direction of its velocity at the initial point?

$A$ particle of mass $m$ and charge $q$ is placed at rest in a uniform electric field $E$ and then released. The kinetic energy attained by the particle after moving a distance $y$ is

$\int \frac{3^x dx}{\sqrt{9^x-1}}$ is equal to

If $x^y=y^x$, then $x(x-y \log x) \frac{d y}{d x}$ is equal to :