Give reasons:
A freely suspended magnet shows
N-S poles at rest.

A freely suspended magnet comes to rest along the N-S direction.

Explanation:

-Irrespective of direction of suspension, the bar eventually comes to rest at earth's N-S direction.

-Bar end that points to Earth's north is called the North Pole. Bar end that point's to earth's south is called the South pole.

-The reason for this default positioning is called the Directive Property. This is because earth acts as an external magnetic field.

answer: the correct answer for the fill in the blank is rods.

rods are the specialized photoreceptor cells that are present in the retina of human eye. they are responsible for vision in the night time ( also called scotopic vision). they have very low visual acuity and color distinguishing ability.

as they are responsible for vision in night time, therefore they are found predominantly in the nocturnal animals.