Two students, student 1 and student 2, did the same experiment simultaneously to measure parallax. student 2's eyes are farther apart than student 1's eyes. the steps of the experiment are listed below. 1. hold the thumb out at arm's length. 2. look at the thumb and alternately open and close each eye. 3. estimate the distance by which the thumb appears to move with respect to background objects. based on the experiment, what would the students most likely conclude about the parallax method of measurement of star distances? a. both the parallax measurements should be taken at the same time b. parallax shift remains the same when measured by different instruments c. the shift in parallax while measuring star distances depends on the distance between the two points of observation d. parallax would be most effective in measuring distances to stars which are more than a billion light years away from earth

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