Menstrual flow occurs due to lack of

$A$ conducting rod $AC$ of length $4l$ is rotated about a point $O$ in a uniform magnetic field $\vec B$ directed into the paper. $AO = l$ and $OC = 3l$. Then:

The maximum value of $ \left(\frac{1}{x}\right)^{x} $ is

The basic functional unit of the human kidney is

Which one of the following pairs is mismatched?

If two events $A$ and $B$ are such that $P(A^c) = 0.3$,$P(B) = 0.4$,and $P(A \cap B^c) = 0.5$,then $P\left[ \frac{B}{A \cup B^c} \right]$ is equal to