To determine which model best represents Oran's setup to model Earth's magnetic field, let's analyze the given options with the information provided.
1. Model 1: The south pole of the bar magnet is placed at the bottom of the ball, and the compass points towards the magnetic south pole.
2. Model 2: The south pole of the bar magnet is placed at the top of the ball, and the compass points towards the magnetic south pole.
3. Model 3: The south pole of the bar magnet is placed at the bottom of the ball, and the compass points towards the magnetic north pole.
4. Model 4: The south pole of the bar magnet is placed at the top of the ball, and the compass points towards the magnetic north pole.
Given Earth's magnetic field behavior, the north pole of a compass needle is attracted to the magnetic south pole of Earth, which is near the geographic north pole.
1. If Oran places the south pole of the bar magnet at the bottom of the ball, it means he is modeling Earth's magnetic north pole at the geographic south pole. Here, the compass will point towards the geographic north, which corresponds to the magnetic south.
2. If Oran places the south pole of the bar magnet at the top of the ball, it means he is modeling Earth's magnetic south pole at the geographic north pole. Here, the compass will point towards the geographic north, which corresponds to the magnetic south.
The correct model that represents Oran's setup, where Earth's magnetic south is near Earth's geographic north, involves placing the south pole of the bar magnet at the top of the ball (geographic north), causing the compass to point towards the magnetic north pole.
Based on this analysis, the suitable representation is:
Model 4:
- The south pole of the bar magnet is placed at the top of the ball (geographic north).
- The compass points towards the magnetic north pole.
Thus, the model that most closely represents Oran's setup is Model 4.
