Options:
A.
B.
C.
Answer:
C.
Explanation:
From the attached image, in the electromagnet above the 3, we can see that the positive terminal comes before the negative terminal at the bottom left.
Now, when it is reversed, they will both move to the bottom right but their position will change with the negative coming before the positive.
- Also, the electric current arrow inside the circle points in the north west direction but when it is reversed, it will point in the north east direction.
- Also, the winded coil over the pole remains the same.
Thus, the only option that fulfills this reversed positions is the 3rd electromagnet