It is hard to see the motion of stars because of their extreme distance from us
true
false

true

explanation:

motion of star is not visible to us because we define motion as change in position of object.

here since stars are far away from us then as per our reference frame we can see that the position of star at a finite angular position

now let say the star moves by some distance near it's position then we will say that the change in its angular position with respect to our position is given by

here r = distance of star from our position

now as we know that distance of star is very large as compare to change in its position so the change in angular position is very small.

so this small change in angular position is not detectable to us and it seems to be stationary for us.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia

the ima (higher than 1m) will be greater than the ima with the height of 1m.