A permanent magnet can exert a magnetic force on which of the following objects?

Introduction / Context:

Permanent magnets and electromagnets are common sources of magnetic fields in physics and technology. Understanding how they interact with each other and with other magnetic materials is important in applications such as motors, loudspeakers, and magnetic locks. This question asks which objects a permanent magnet can affect.

Given Data / Assumptions:

• We have at least one permanent magnet.
• We consider its interaction with other permanent magnets and with electromagnets.
• Both devices create magnetic fields in the surrounding space.

Concept / Approach:

A permanent magnet has a fixed magnetic field due to the alignment of magnetic domains in its material. An electromagnet generates a magnetic field when electric current flows through its coil. Magnetic forces arise whenever magnetic fields interact with magnetic materials or with other sources of magnetic field. Therefore, a permanent magnet can attract or repel another permanent magnet, and it can also interact with an electromagnet because both create magnetic fields that can influence each other.

Step-by-Step Solution:

Verification / Alternative check:

In many devices, such as electric motors, permanent magnets and electromagnets are used together. The rotor or stator may be a permanent magnet, while the other part is an electromagnet. The fact that these devices work is practical proof that permanent magnets and electromagnets can influence each other strongly.

Why Other Options Are Wrong:

Option A: Only other permanent magnets is too restrictive because it ignores the clear interaction with electromagnets.

Option B: Only electromagnets carrying current is also incomplete because permanent magnets clearly attract or repel each other as well.

Option D: Neither permanent magnets nor electromagnets is completely wrong because we know magnets do exert forces.

Common Pitfalls:

One mistake is to think of electromagnets and permanent magnets as completely different categories that do not interact. In reality, both produce magnetic fields and obey the same laws. Another confusion occurs if students think that only moving charges interact with magnets, but in fact magnetic fields interact regardless of whether they come from permanent alignment or from current.

Final Answer:

A permanent magnet can affect both permanent magnets and electromagnets.