Exploring Permanent Magnets

Abass is conducting an experiment in her physics class. What are the key properties of permanent magnets that she should be aware of?

• Attraction to all materials regardless of composition

• Magnetic polarity that changes frequently

• Key properties of permanent magnets include: 1) Fixed magnetic polarity, 2) Ability to attract ferromagnetic materials, 3) Resistance to demagnetization, 4) Retention of magnetism over time.

• Ability to generate electricity

In a science class, Saad is curious about how permanent magnets differ from temporary magnets. Can you help him understand?

• Permanent magnets are always magnetized, whereas temporary magnets are magnetized only in the presence of an external magnetic field.

• Permanent magnets lose their magnetism over time while temporary magnets do not.

• Permanent magnets can be turned on and off like a switch.

• Temporary magnets are always magnetized, regardless of external fields.

Nazrul is conducting an experiment to understand the role of magnetic domains in permanent magnets. What did she discover?

• Magnetic domains repel each other to weaken the magnetic field.

• Magnetic domains in permanent magnets are aligned to create a strong and stable magnetic field.

• Magnetic domains are randomly oriented in permanent magnets.

• Magnetic domains only exist in temporary magnets.

List three common applications of permanent magnets.

• Light bulbs

• Solar panels

• Batteries

• Electric motors, magnetic locks, refrigerator magnets

What is the process of magnetization?

• The process of magnetization involves heating the material to high temperatures.

• Magnetization occurs when a material is submerged in water.

• The process of magnetization is achieved by applying a strong electric current.

• The process of magnetization involves aligning the magnetic domains of a material, often through exposure to an external magnetic field.

Raghad is curious about how a permanent magnet can be demagnetized. Can you help her understand?

• Coating the magnet with oil

• A permanent magnet can be demagnetized by heating, applying an alternating magnetic field, or mechanical shock.

• Exposing the magnet to sunlight

• Placing the magnet in water

What materials are typically used to make permanent magnets?

• Gold, silver, platinum

• Copper, aluminum, zinc

• Lead, tin, mercury

• Iron, cobalt, nickel, neodymium-iron-boron, samarium-cobalt

What is the difference between ferromagnetic and paramagnetic materials?

• Ferromagnetic materials retain magnetization; paramagnetic materials do not.

• Ferromagnetic materials are always non-magnetic; paramagnetic materials are always magnetic.

• Ferromagnetic materials lose magnetization at high temperatures; paramagnetic materials retain magnetization at all temperatures.

• Ferromagnetic materials can only be found in metals; paramagnetic materials can be found in insulators.

What is the effect of temperature on the strength of a permanent magnet?

• Increasing temperature increases the strength of a permanent magnet.

• Temperature has no effect on the strength of a permanent magnet.

• Decreasing temperature decreases the strength of a permanent magnet.

• Increasing temperature decreases the strength of a permanent magnet.

Describe a real-world example of a permanent magnet in use.

• Magnetic levitation trains use superconductors.

• Electric motors use temporary magnets.

• Refrigerator magnets are a real-world example of permanent magnets in use.

• Magnetic compasses rely on electromagnets.