In the conversion of a zinc ore to zinc metal,the process of roasting involves:

$A$ stationary horizontal disc is free to rotate about its axis. When a torque is applied on it,its kinetic energy as a function of $\theta$,where $\theta$ is the angle by which it has rotated,is given as $K \theta^2$. If its moment of inertia is $I$,then the angular acceleration of the disc is:

Using the digits $0, 2, 4, 6, 8$ not more than once in any number,the number of $5$-digit numbers that can be formed is:

All but one of the following compounds react with aniline to give acetanilide. Which one does not?

Which of the following compounds is non-polar?

Which of the following is a copper-releasing $IUD$?