A region of space where magnetic forces can be detected
What does Newtons per Ampere-meter (N/A⋅m) measure?
Magnetic field strength
What is coercivity in a permanent magnet?
Resistance to demagnetization
Alnico magnets are used in electric motors and guitar pickups.
What is the shape of the magnetic field lines around a straight wire carrying current?
Concentric circles
The magnetic field lines for a straight wire carrying current form concentric circles around the wire
Inside a solenoid, the magnetic field lines are uniform and parallel
A permanent magnet retains its magnetic field after the magnetizing field is removed
What type of permanent magnet is used in magnetic resonance imaging (MRI)?
Neodymium
What is the shape of the magnetic field generated by a straight wire according to Ampère's Law?
Circular
The magnetic force between two poles is inversely proportional to the square of the distance
Faraday's law of electromagnetic induction states that the induced electromotive force (EMF) is equal to the negative rate of change of magnetic flux
Faraday's law states that the induced electromotive force (EMF) is equal to the rate of change of magnetic flux.
True
If the magnetic field is increasing, the induced current opposes the increase.
True
Match the type of permanent magnet with its properties and uses:
Ferrite ↔️ Low strength, loudspeakers
Alnico ↔️ Moderate strength, electric motors
Neodymium ↔️ Very high strength, hard drives
Samarium-Cobalt ↔️ High strength, aerospace applications
A solenoid generates a magnetic field similar to a bar magnet inside.
True
What does the term μ0 in Ampère's Law represent?
Permeability of free space
The magnetic field lines for a straight wire carrying current form concentric circles
Electromagnetic induction is described by Faraday's law, which states that the induced electromotive force (EMF) is equal to the negative rate of change of magnetic flux
What is the right-hand rule used to determine?
Magnetic field direction
Magnetic field strength is measured in Tesla
Tesla (T) measures magnetic flux density, which is the force per unit area perpendicular to the field.
True
What is retentivity in a permanent magnet?
Ability to maintain magnetism
Ferrite magnets are commonly used in loudspeakers and refrigerator magnets due to their low cost.
True
Order the shapes of magnetic fields generated by different current configurations:
1️⃣ Straight Wire: Circular around the wire
2️⃣ Loop: Forms concentric rings with a strong field at the center
3️⃣ Solenoid: Uniform inside, similar to a bar magnet
What is the shape of the magnetic field lines inside a solenoid?
Uniform and parallel
Match the current configuration with its magnetic field shape:
Straight Wire ↔️ Circular around the wire
Loop ↔️ Concentric rings with strong field at center
Solenoid ↔️ Uniform and parallel, like a bar magnet
A Tesla measures the magnetic flux density.
True
Ferrite magnets are commonly used in loudspeakers due to their low cost.
True
Ampère's Law describes how electric currents generate magnetic fields.
True
Like magnetic poles repel each other
What is the process of generating an electric current from a changing magnetic field called?
Electromagnetic induction
Electromagnetic induction is described by Faraday's law of electromagnetic induction.
The direction of the induced current is determined by Lenz's law.
The strength of a magnetic field is measured in Tesla or Newtons per Ampere-meter.
What law describes how electric currents generate magnetic fields?
Ampère's Law
Electric currents generate magnetic fields as described by Ampère's Law
Match the current configuration with its magnetic field shape:
Straight Wire ↔️ Circular around the wire
Loop ↔️ Concentric rings with strong field at center
Solenoid ↔️ Uniform inside, like a bar magnet
What is the formula for calculating the magnetic force between two poles?
F = \frac{k \cdot m_{1} \cdot m_{2}}{r^{2}}</latex>
Arrange the relationships between changes in the magnetic field and the direction of the induced current: