FISIKA KELAS XII | INDUKSI ELEKTROMAGNETIK - Fluks Magnet, Hukum Faraday, dan Hukum Lenz

Summary

This video by Yusuf Ahmad introduces the concept of electromagnetic induction, explaining its definition and the difference between electromagnetic induction and magnetic induction. It covers key principles such as magnetic flux, Faraday's Law, and Lenz's Law, providing mathematical formulas for each concept. The video also includes practical examples to illustrate how induced electromotive force (EMF) can be calculated using changes in magnetic flux. This engaging lesson serves as a foundational understanding of electromagnetic principles, preparing viewers for future applications of the topic.

Takeaways

• 😀 Electromagnetic induction is the generation of electric current due to changes in magnetic fields or magnetic flux.
• 😀 Unlike magnetic induction, which is caused by electric current producing a magnetic field, electromagnetic induction works in the opposite way.
• 😀 Magnetic flux is defined as the quantity of magnetic field lines passing through a given area.
• 😀 The mathematical formula for magnetic flux includes the magnetic field strength, area, and the angle between the magnetic field and the normal to the surface.
• 😀 Faraday's law states that moving a magnet in and out of a coil induces an electric current, evidenced by a deflection in a galvanometer.
• 😀 If the magnet is stationary, there is no induced current, highlighting the necessity of movement for induction to occur.
• 😀 The induced current, known as induced electromotive force (EMF), is proportional to the rate of change of magnetic flux.
• 😀 Lenz's law indicates that the direction of induced current will always oppose the change that produced it.
• 😀 The presentation includes example problems that demonstrate how to calculate induced EMF using Faraday's law and Lenz's law.
• 😀 The upcoming videos will cover further applications and concepts related to electromagnetic induction.

Q & A

What is electromagnetic induction?

Electromagnetic induction is the process by which an electric current is generated in a conductor due to a change in the magnetic field or magnetic flux.

How is magnetic flux defined?

Magnetic flux is defined as the amount of magnetic field lines passing through a given area and is mathematically expressed as Φ = B · A · cos(θ), where B is the magnetic field strength, A is the area, and θ is the angle between the magnetic field lines and the normal to the surface.

What is Faraday's Law of Induction?

Faraday's Law states that the induced electromotive force (EMF) in a circuit is equal to the rate of change of magnetic flux through the circuit, mathematically given by ε = -N (ΔΦ/Δt), where N is the number of turns in the coil.

What does Lenz's Law state?

Lenz's Law states that the direction of induced current in a conductor will be such that it opposes the change in magnetic flux that produced it, ensuring energy conservation.

How can the magnetic flux be calculated when the magnetic field is perpendicular to the surface?

When the magnetic field is perpendicular to the surface (θ = 0°), the magnetic flux can be simplified to Φ = B · A since cos(0°) = 1.

What happens to the galvanometer reading when a magnet is moved in and out of a coil?

When a magnet is moved in and out of a coil, the galvanometer shows a deflection, indicating that an electric current is induced in the coil. If the magnet remains stationary, there is no deflection, meaning no current is induced.

What is the formula to calculate induced EMF when the magnetic flux is changing?

The induced EMF can be calculated using the formula ε = -N (ΔΦ/Δt), where ΔΦ is the change in magnetic flux and Δt is the time interval over which the change occurs.

In the provided example, what was the induced EMF when the magnetic flux changed from 9 × 10^-5 Weber to 3 × 10^-5 Weber?

The induced EMF calculated was 6 volts.

How do you find the induced EMF when given a function for magnetic flux?

To find the induced EMF from a flux function, differentiate the flux with respect to time and apply Faraday's Law: ε = -N (dΦ/dt).

What are some applications of electromagnetic induction mentioned in the video?

The video mentions the principles of electromagnetic induction but indicates that further applications will be covered in future videos, suggesting practical uses in technology like generators and transformers.