Question

If uncertainty in position of the electron is ____, then the uncertainty in its momentum would be infinity.

Answer 1

If the uncertain position of an electron would be zero then we would have no idea of where the electron is.
It follows that the momentum will be infinite.

$\Delta x$ . $\Delta$p $\ge$ $\frac{h}{4\pi }$

So, if $\Delta p=$ infinity

Then $\Delta x=0$.