After taking an astronomy class, you purchase an astronomical telescope that has a focal length for the objective and eyepiece respectively of 173 cm and 1.20 cm. After using the telescope several times, you decide to increase its angular magnification by replacing the eyepiece. After replacing the eyepiece, the length of the barrel must be adjusted in order to bring objects into focus. Determine the best angular magnification you can obtain, if the barrel can only be shortened by 0.51 cm from its current length.

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explanation:

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

a. carbon monoxide from car exhaust

b.particulate matter, such as soot

c.water vapor from a factory smokestack

d.acid rain

these are the answer choices im on that question right now