Question

1. how is a magnet able to pick up bits of metal without actually touching them? a. the magnet is surrounded by an electric field that attracts the metal. b. the metal exerts a repulsive force on the magnet. c. there is an invisible magnetic field around the magnet where it exerts magnetic force. d. the electric force from the magnet attracts the bits of metal. 8. explain phenomena a magnet is placed on a refrigerator to hold up a calendar. as the magnet approaches the refrigerator, the potential energy between the magnet and the refrigerator decreases. explain why.

Explanation:

Question 7:

A magnet can pick up bits of metal without touching them because there is an invisible magnetic field around the magnet where it exerts magnetic force. Magnets create magnetic fields that can attract ferromagnetic materials like iron, nickel, and cobalt. Option A is incorrect as it mentions an electric field instead of a magnetic field. Option B is wrong because the metal is attracted, not exerting a repulsive force on the magnet in this context. Option D is incorrect since it's the magnetic force, not electric force, at play here.

Question 8:

Potential energy in a magnetic - system is related to the position of the magnet relative to the magnetic object (the refrigerator in this case). As the magnet approaches the refrigerator, it moves from a state of higher potential energy to a state of lower potential energy. This is similar to an object in a gravitational field moving towards the source of the field. The magnetic force does work on the magnet as it moves closer to the refrigerator, converting the potential energy into other forms (such as kinetic energy if the magnet is free - moving initially) or just reducing the stored potential energy due to the attractive interaction between the magnet and the ferromagnetic material of the refrigerator.

Answer:

Question 7: C. There is an invisible magnetic field around the magnet where it exerts magnetic force.

Question 8: As the magnet approaches the refrigerator, the magnetic force does work on the magnet. This work is done at the expense of the potential energy stored in the magnetic - interaction system. The closer the magnet gets to the refrigerator, the lower the potential energy becomes, similar to an object falling in a gravitational field where the potential energy decreases as the object moves closer to the source of the gravitational field.