Magnetism Flashcards
What is magnetism?
Magnetism is a physical phenomenon produced by the motion of electric charge, which results in attractive and repulsive forces between objects.
True or False: All materials are magnetic.
False.
What are the two types of magnetic poles?
North and South poles.
Fill in the blank: Magnetic fields are represented by _____ lines.
field.
What is a magnetic field?
A magnetic field is a region around a magnetic material or a moving electric charge within which the force of magnetism acts.
What unit is used to measure magnetic field strength?
Tesla.
True or False: Opposite magnetic poles attract each other.
True.
What is an electromagnet?
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current.
How can the strength of an electromagnet be increased?
By increasing the electric current or adding more coils of wire.
What is the main use of electromagnets?
Electromagnets are commonly used in devices like electric motors, generators, and magnetic locks.
Fill in the blank: The area around a magnet where magnetic forces can be detected is called the _____ field.
magnetic.
What happens to the magnetic field when the current in an electromagnet is turned off?
The magnetic field disappears.
Multiple choice: Which material is commonly used as a core for electromagnets? A) Plastic B) Iron C) Wood
B) Iron.
What is the right-hand rule used for?
The right-hand rule is used to determine the direction of the magnetic field around a current-carrying conductor.
True or False: The Earth itself acts like a giant magnet.
True.
What is the role of a commutator in an electric motor?
A commutator reverses the direction of current flow in the motor windings to ensure continuous rotation.
What is the relationship between electricity and magnetism known as?
Electromagnetism.
Multiple choice: What is one application of electromagnets? A) Fridge magnets B) MRI machines C) Paper clips
B) MRI machines
What is a permanent magnet?
A permanent magnet is a material that maintains a persistent magnetic field without the need for an external power source.
True or False: Magnetic fields can pass through non-magnetic materials.
True
What is the primary function of magnetic shielding?
Magnetic shielding is used to protect sensitive electronic equipment from external magnetic fields.
Fill in the blank: The interaction between two magnetic fields can result in _____ or _____ forces.
Attractive; repulsive
What determines the strength of a magnetic field?
The strength of the magnetic field is determined by the amount of electric current and the distance from the source.
Multiple choice: Which of the following is NOT a type of magnet? A) Temporary B) Permanent C) Static
C) Static
What is magnetic flux?
Magnetic flux is the measure of the quantity of magnetism, taking into account the strength and the extent of a magnetic field.
True or False: The direction of a magnetic field is always from the north pole to the south pole.
True
What is Faraday’s law of electromagnetic induction?
Faraday’s law states that a changing magnetic field within a closed loop induces an electromotive force (EMF) in the loop.
Fill in the blank: The phenomenon where an electric current is generated by a changing magnetic field is called _____ induction.
Electromagnetic.
What is a solenoid?
A solenoid is a coil of wire that generates a magnetic field when an electric current passes through it.
Multiple choice: What effect does increasing the number of coils in a solenoid have on the magnetic field? A) Decreases it B) Increases it C) Has no effect
B) Increases it.
What are magnetic domains?
Magnetic domains are regions within a magnetic material where the magnetic moments of atoms are aligned in the same direction.
True or False: Electromagnets can be turned on and off.
True.
What is the use of magnetic levitation?
Magnetic levitation is used to lift and propel objects without contact, commonly seen in maglev trains.
What is a magnetic field line?
A magnetic field line is a visual representation of the magnetic field, showing the direction and strength of the field.
A student places a bar magnet on a table and sprinkles iron filings around it. Describe what will happen to the iron filings and explain why this occurs.
The iron filings will align along the magnetic field lines, forming distinct patterns that show the shape of the field. This happens because iron filings become temporary magnets when placed in the magnetic field of the bar magnet, causing them to be attracted and arranged along the field lines from north to south.
How can a student use a compass to show the direction of the magnetic field around the bar magnet?
The student can place a small plotting compass near one pole of the magnet and mark the direction in which the compass needle points. Then, they move the compass a small distance along the direction of the needle and mark the new position. By repeating this process and connecting the marked points with arrows, the student can draw the shape and direction of the magnetic field lines, which always point from the north pole to the south pole outside the magnet.
