To explain why the magnetic force acting on compass 1 is greater than the magnetic force acting on compass 3, we need to consider the factors that affect the magnetic force on a compass needle.
Distance from the magnet: The magnetic force decreases with increasing distance from the magnet. If compass 1 is closer to the magnet than compass 3, it will experience a stronger magnetic force.
Strength of the magnet: The magnetic force is directly proportional to the strength of the magnet. If the magnet near compass 1 is stronger than the magnet near compass 3, it will exert a greater magnetic force on compass 1.
Alignment with the magnetic field: The magnetic force on a compass needle depends on its alignment with the magnetic field. When a compass needle is parallel to the magnetic field lines, it experiences maximum force. If compass 1 is more aligned with the magnetic field compared to compass 3, it will experience a stronger magnetic force.
Angle between the magnetic field and the compass needle: The magnetic force is strongest when the angle between the magnetic field and the compass needle is 90 degrees. If compass 1 has a smaller angle with the magnetic field compared to compass 3, it will experience a larger magnetic force.
Based on these factors, if compass 1 is closer to a stronger magnet, more aligned with the magnetic field, and has a smaller angle with the magnetic field compared to compass 3, it will experience a greater magnetic force.
I hope this helps! :)