Magnetism & Electromagnetism Flashcards
To understand and apply the principles of energy transfers, conservation of energy, and efficiency, as well as the mechanisms of thermal energy transfer, the concept of work and power, and different energy resources. This knowledge will be used to solve problems and analyze real-world applications, aligning with the Pearson Edexcel International GCSE Physics syllabus.
What is MAGNET?
A magnet is an object that produces a magnetic field, attracting materials
What are MAGNETIC MATERIALS?
1.iron
2.Nickel
3.cobalt
What is MAGNETISM ?
Magnetism is the force of attraction or repulsion that acts between magnetic materials
What are HARD MAGNETS?
These materials are difficult to magnetise but retain their magnetism for a long time.
What are SOFT MAGNETS?
These materials are easily magnetised and demagnetised.
What is a MAGNETIC POLE?
Magnetic poles are the parts of a magnet that exert the greatest force.
What is MAGNETIC FIELD LINE?
A magnetic field line is a visual representation of the magnetic field around a magnet or current-carrying conductor.
Function of MAGNETIC FIELD LINE
These lines indicates,
direction
Strength
How is magnetism INDUCED in materials when they are PLACED IN A MAGNETIC FIELD?
EXPOSURE TO THE MAGNETIC FIELD
When a material is placed in a magnetic field, the external field interacts with the magnetic domains within the material.
How can you investigate the magnetic field pattern for a permanent bar magnet and between two bar magnets using PLOTTING COMPASSES ?
1.PLACE THE MAGNET
Position the bar magnet on a flat surface.
2.USE THE PLOTTING COMPASSES
Place the plotting compass at various points around the magnet. The compass needle will align with the local magnetic field direction.
3.RECORD THE DIRECTIONS
Note the direction in which the compass needle points at each location.
4.DRAW THE FIELD LINES
Place the bar magnet on a flat surface and cover it with a sheet of paper or transparent plastic.
Sprinkle iron dust or iron filings evenly over the paper/plastic.
Gently tap the surface to help the iron dust align with the magnetic field.
Observe the pattern of the iron dust, which will show lines emerging from the north pole and curving around to the south pole, revealing the magnetic field pattern.
How to use two permanent magnets to produce a UNIFORM MAGNETIC field pattern?
MAGNETIC FIELD INTERACTION BETWEEN 2 BAR MAGNETS
The fields from each magnet combine and overlap in the region between them.
FIELD LINE FORMATION
The magnetic field lines extend from the north pole of one magnet to the south pole of the other, forming parallel lines between the magnets.
What is Earth’s MAGNETIC field?
Earth’s magnetic field is a protective magnetic shield created by the movement of molten iron in the Earth’s core, extending from the planet’s interior into space.
Describe the RELATIONSHIP between ELECTRIC CURRENT and MAGNETIC FIELDS?
When an electric current flows through a conductor, it produces a magnetic field around it, which is a fundamental principle of electromagnetism.
What is a ELECTROMAGNET?
An electromagnet is a type of magnet where the magnetic field is produced by an electric current, typically consisting of a coil of wire wound around a ferromagnetic core.
How does the** RIGHT-HAND RULE** help in determining the direction of the magnetic field?
The right-hand rule states that if you point your right thumb in the direction of the current, your fingers will curl in the direction of the magnetic field lines.
What happens to the STRENGTH of the magnetic field as the distance from the conductor increases?
The strength of the magnetic field decreases with distance from the conductor.
Explain the working** principle** of an ELECTROMAGNET.
When an electric current flows through the coil of an electromagnet, it generates a magnetic field, and the ferromagnetic core inside the coil amplifies this magnetic field.
List some** common USES **of electromagnets.
Electromagnets are used in devices like ELECTRIC MOTERS, YARD CRANES , and RELAYS due to their ability to turn the magnetic field on and off.
Describe the MAGNETIC FIELD pattern generated by a current flowing through a STRAIGHT wire.
A current flowing through a straight wire generates a magnetic field in the form of concentric circles around the wire.
How does the STRENGTH OF MAGNETIC FIELD relate to the current flowing through a conductor?
The strength of the magnetic field increases with the current flowing through the conductor.
Describe the STRENGTH of a magnetic field in relation to DISTANCE from a wire.
The magnetic field is strongest closest to the wire and gets weaker as you move away.
Define the magnetic field pattern around a FLAT CIRCULAR COIL
The magnetic field around a flat circular coil forms loops, with a denser field in the center where the loops overlap, creating a STRONGER MAGNETIC EFFECT.
How does the magnetic field of a SOLENOID compare to that of a bar magnet?
The magnetic field inside a solenoid resembles the field of a bar magnet, with distinct north and south poles.
What factors INFLUENCE the strength of a solenoid’s magnetic field?
The strength of a solenoid’s magnetic field depends on,
- the current flowing through it
- & The number of turns in the coil
- & and the presence of a ferromagnetic core.
How does Fleming’s Left-Hand Rule assist in understanding the behaviour of current-carrying wires in magnetic fields?
It predicts the direction of the force acting on the wire by using the thumb for force direction, the first finger for magnetic field direction, and the second finger for current direction.
Explain the practical applications of the force on a current-carrying wire in a magnetic field.
This principle is essential in the functioning of electric motors and loudspeakers, where the force causes rotation or sound production.
What does the THUMB represent in Fleming’s Left-Hand Rule?
The thumb represents the direction of the force (motion) on the conductor.
How is the direction of the magnetic field indicated in Fleming’s Left-Hand Rule?
The first finger indicates the direction of the magnetic field, which is from north to south.
What does the SECOND FINGER represent in Fleming’s Left-Hand Rule?
The second finger represents the direction of the current, flowing from positive to negative.
Describe the** USEFULLNESS** of Fleming’s Left-Hand Rule in analyzing devices like motors and generators.
It is particularly useful for understanding the
- interaction between current and magnetic fields
- which is fundamental to the operation of these devices.
Describe the factors that affect the force on a current-carrying conductor in a magnetic field.
The force on a current-carrying conductor depends on,
- the strength of the magnetic field
- the current in the wire
- and the angle between the field and the current.
How does the STRENGTH of the magnetic field INFLUENCE the force on a current-carrying wire?
A stronger magnetic field results in a larger force on the current-carrying wire.
Define the RELATIONSHIP between current in the wire and the force experienced by it.
The greater the current flowing through the conductor, the larger the force experienced by the wire.
