FISIKA Kelas 12 - Medan Magnetik | GIA Academy

Summary

In this educational video from Gia Academy, viewers learn about magnetic fields and their applications in transportation, specifically focusing on maglev trains. The video explains key concepts such as magnetic induction, the principles discovered by Hans Christian Ørsted, and the laws governing magnetic fields produced by electric currents. It covers various scenarios involving straight wires, circular wires, solenoids, and toroids, providing mathematical formulas and visual examples to illustrate how to calculate and determine the direction of magnetic induction. The session concludes with example problems to reinforce understanding of the concepts presented.

Takeaways

• 😀 Magnetic fields are the result of the space around magnets and electric currents, which exert magnetic forces.
• 😀 Magnetic fields can be created by both permanent magnets and electric conductors carrying current.
• 😀 Hans Christian Ørsted discovered the relationship between electricity and magnetism in 1820, showing how electric currents influence magnetic fields.
• 😀 Biot-Savart Law describes how the strength of a magnetic field around a conductor is related to the current, wire length, and distance from the point of observation.
• 😀 The unit of magnetic induction is Tesla (T), and other units like Gauss and Maxwell per square centimeter are also used.
• 😀 The right-hand rule is essential for determining the direction of magnetic induction, where the thumb points in the direction of the current and fingers curl to indicate the magnetic field.
• 😀 The magnetic field around a straight conductor can be calculated using the formula B = (μ₀ * I) / (2 * π * r), where μ₀ is the magnetic permeability of free space.
• 😀 For a circular loop of wire, the magnetic induction at the center of the loop is calculated with the formula B = (μ₀ * n * I) / (2 * r), where n is the number of loops and I is the current.
• 😀 A solenoid, a coil of wire, generates a uniform magnetic field, and the field strength at the center is determined by B = (μ₀ * n * I) / l, where l is the length of the solenoid.
• 😀 Toroids, which are circular solenoids, generate a magnetic field that can be calculated using the formula B = (μ₀ * n * I) / (2 * π * r), where r is the radius of the toroid.
• 😀 Various examples and problems are provided to help understand the application of these concepts in real-life scenarios, such as magnetic fields in long wires, coils, and solenoids.

Q & A

What is a maglev train and how does it relate to magnetic fields?

A maglev train, or magnetic levitation train, utilizes magnetic fields for transportation. It is an application of magnetic fields in transport, allowing trains to float above tracks and move at high speeds.

What is a magnetic field?

A magnetic field is a region around a magnet where magnetic forces can be observed. It is produced by permanent magnets or electric currents and can influence other magnets and charged particles within the field.

Who was Hans Christian Ørsted and what did he discover?

Hans Christian Ørsted was a Danish scientist who discovered the relationship between electricity and magnetism in 1820. He found that an electric current could influence a nearby compass needle, demonstrating that electric currents generate magnetic fields.

What is the Biot-Savart Law?

The Biot-Savart Law describes the magnetic field generated by an electric current. It states that the magnetic induction at a point is directly proportional to the current and the length of the conductor and inversely proportional to the square of the distance from the conductor.

How can you determine the direction of the magnetic field around a conductor?

The direction of the magnetic field around a conductor can be determined using the right-hand rule. If you grasp the conductor with your right hand, with your thumb pointing in the direction of the current, your fingers will curl in the direction of the magnetic field lines.

What are some different units of magnetic induction?

Magnetic induction can be measured in several units, including Tesla, Gauss, and Maxwell per square centimeter. One Tesla equals 10,000 Gauss.

What is the formula for calculating the magnetic induction produced by a long straight conductor?

The magnetic induction (B) around a long straight conductor can be calculated using the formula B = μ₀ * I / (2π * r), where μ₀ is the permeability of free space, I is the current, and r is the distance from the conductor.

How is the magnetic induction calculated for a solenoid?

The magnetic induction at the center of a solenoid can be calculated with the formula B = μ₀ * n * I, where n is the number of turns per unit length and I is the current flowing through the solenoid.

What happens to the magnetic field inside a toroid?

The magnetic field inside a toroid can be calculated using the formula B = μ₀ * n * I / (2π * r), where n is the number of turns, I is the current, and r is the radius of the toroid. The field is uniform inside the toroid and zero outside.

What are the applications of magnetic fields in technology?

Magnetic fields are used in various technologies, including maglev trains, magnetic resonance imaging (MRI), electric motors, and generators, among others. They are crucial in many modern devices and transportation systems.