I think the correct answer would be that because electromagnets are powerful and can be turned off and on anytime. Electromagnet is a magnet in which the magnetic field is made by the electric current that is induced to the system.
Answer:

Explanation:
As we know that electric field due to infinite line charge distribution at some distance from it is given as

now we need to find the electric field at mid point of two wires
So here we need to add the field due to two wires as they are oppositely charged
Now we will have

now plug in all data



now we have



Answer:
gravity
Explanation:
as the earth rotates on an axis, it causes an effect known as centripetal acceleration with is an acceleration that pulls objects towards the center of the object. in planets, we call this Gravity
Answer: it would be A
Explanation: how are we to measure the air of a square mile