Magnetsm I - SS3 Physics Past Questions and Answers - page 2
When two magnets are brought together, what determines whether they will attract or repel each other?
The size of the magnets
The material the magnets are made of
The strength and orientation of their magnetic fields
The distance between the magnets
Which of the following is an example of a non-magnetic material?
Iron
Steel
Copper
Aluminum
What is a magnetic field and its determinants?
Magnetic fields are regions in space around a magnet or a current-carrying conductor where magnetic forces are exerted on magnetic materials. They are regions in space where magnetic forces are exerted on magnetic materials. The strength and direction of the magnetic field are determined by the strength and direction of the current flow or magnetization.
How do magnetic forces work?
Magnetic forces are exerted on magnetic materials in the presence of magnetic fields. Like charges repel each other, and opposite charges attract each other. Similarly, like magnetic poles repel each other, and opposite magnetic poles attract each other. The force between two magnetic poles is proportional to the product of their pole strengths and inversely proportional to the square of the distance between them.
Which of the following materials is not ferromagnetic?
Iron
Cobalt
Nickel
Aluminum
What is the magnetic property of a material that is weakly attracted to a magnet when placed near it?
Ferromagnetic
Paramagnetic
Diamagnetic
None of the above
Which of the following statements about diamagnetic materials is true?
They have a net magnetic moment even in the absence of an external magnetic field.
They are strongly attracted to magnets.
They have a negative magnetic susceptibility.
They can become permanently magnetized.
Which of the following materials has the highest magnetic susceptibility?
Iron
Cobalt
Nickel
Oxygen
Which of the following materials is ferromagnetic only below a certain temperature?
Iron
Cobalt
Nickel
Gadolinium
Explain the difference between ferromagnetism, diamagnetism, and paramagnetism.
Ferromagnetism is a property of materials that have a strong magnetic response in the presence of an external magnetic field. These materials, such as iron, nickel, and cobalt, have a large magnetic moment due to the alignment of their electron spins.
Diamagnetism, on the other hand, is a property of materials that have a weak magnetic response in the presence of an external magnetic field. These materials have all of their electron spins paired and therefore have no net magnetic moment. Paramagnetism is a property of materials that have a weak magnetic response in the absence of an external magnetic field but have a strong magnetic response in the presence of an external magnetic field. These materials have some unpaired electron spins, which cause a net magnetic moment.