Which of the following is logically equivalent to $\sim(\sim p \Rightarrow q)$?

Which one of the following pairs of hormones can easily pass through the cell membrane of a target cell and bind to a receptor inside it (mostly in the nucleus)?

The radioactive sources $A$ and $B$ have half-lives of $2 \ hr$ and $4 \ hr$ respectively and initially contain the same number of radioactive atoms. At the end of $2 \ hr$,the ratio of their rates of disintegration is:

$A$ spherical portion has been removed from a solid sphere having a charge distributed uniformly in its volume as shown in the figure. The electric field inside the emptied space is

Which of the following is the correct order for basic strength?

$\frac{\sin \theta}{1 - \cot \theta} + \frac{\cos \theta}{1 - \tan \theta} = $