Saltatory conduction is observed in which of the following?

During the transmission of a nerve impulse,the potential inside the membrane undergoes which of the following changes in charge?

In which state is a polarized nerve fiber found?

The nerve fibre in its resting stage is

During the propagation of a nerve impulse,the action potential results from the movement of

Select the correct sequence of statements regarding the conduction of a nerve impulse and select the correct option given below.
$i.$ Rapid influx of $Na^{+}$ inside the axon.
$ii.$ $Na^{+}$ gates are closed and $K^{+}$ gates open after the refractory period.
$iii.$ Intracellular fluid is electronegative and the potential difference is $-70 \ mV$.
$iv.$ Extracellular fluid becomes electronegative.
$v.$ Disturbance to the resting potential.