21
practice examMultiple Choice

Practice Exam

Question 21 • Physics in the Universe

Hiro wants to model the magnetic field of a bar magnet using a shoe box and pipe cleaners. He labels the ends of the shoe box N and S. How should he position the pipe cleaners? Choose three correct answers.

Answer
A
They should form loops outside of the box over the top, bottom, and sides of the box.
B
They should exit the box at N and enter at S.
C
They should be put inside the box so the two ends join.
D
They should form loops outside of the box, but over only the sides of the box.
E
They should exit the box at S and enter at N.
F
None should be put inside the box.

Explanation

Magnetic field lines form continuous loops. Outside the magnet, they leave the north pole and curve around to enter the south pole, so the pipe cleaners should loop over the top, bottom, and sides. Inside the box, they represent the return path from south to north, joining the ends of each loop.

AI-written and checked against the verified answer.

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