Questions

When the piece of iron is lowered into the water, the water level in the bucket increases. And so the pressure at the bottom of bucket also increases. Thus the total thrust at bottom also increases. Therefore the spring balance reading increases. Thus (a) is correct.

The trajectory of the bullet is a parabola

The eye can see images separately only if they are exhibited at an interval of more than 1/10 of a second. In the case of a movie, the still pictures come one after the other at less than this minimum interval. So we do not see them separately but only as a continuous moving picture.

Prokaryotic cells lack a nucleus and do not have an extensive system of interior membranes. They are encased in a cell wall and many contain external structures such as a capsule, flagellum, or pili. Prokaryotes – have a relatively uniform interior that is not subdivided by internal membranes.