Medan Magnetik • Part 5: Gaya Lorentz Pada Kawat Berarus Listrik

Summary

This video covers the concept of Lorentz force on a current-carrying wire, a key topic in electromagnetism. It explains the theory behind the magnetic force experienced by a wire carrying an electric current in a magnetic field, using practical examples and formulas. The video discusses how to calculate the force using the formula FL = BIL sin(θ), and provides step-by-step guidance on applying the right-hand rule to determine the direction of the force. Several examples involving different wire configurations are explored, including parallel current-carrying wires and forces between them. Overall, it's a comprehensive guide for high school students studying this topic in physics.

Takeaways

• 😀 Lorentz force on a current-carrying wire is the force experienced due to the interaction between the wire's magnetic field and an external magnetic field.
• 😀 The formula for calculating the Lorentz force is FL = B * I * L * sin(α), where B is the magnetic field strength, I is the current, L is the length of the wire, and α is the angle between the magnetic field and the wire.
• 😀 The Lorentz force is a vector, meaning it has both magnitude and direction, which can be determined using the right-hand rule.
• 😀 The right-hand rule for the Lorentz force involves pointing the thumb in the direction of the current (I), the fingers in the direction of the magnetic field (B), and the palm shows the direction of the force (F).
• 😀 An example calculation is given where a 2-meter-long wire with a current of 50 amperes is placed in a 0.03 Tesla magnetic field at a 30° angle, and the resulting Lorentz force is calculated as 1.5 N.
• 😀 Two parallel current-carrying wires exert forces on each other, with the force per unit length (F/L) given by the formula F/L = (μ₀ * I1 * I2) / (2 * π * d), where I1 and I2 are the currents and d is the distance between the wires.
• 😀 If the currents in the wires flow in the same direction, the wires will attract each other; if the currents flow in opposite directions, they will repel each other.
• 😀 A detailed example is provided with two wires experiencing an attractive force due to parallel currents in the same direction, demonstrating how to apply the right-hand rule and calculate the forces on the wires.
• 😀 The script emphasizes the importance of understanding the directionality of the force, particularly in complex situations involving multiple wires or magnetic fields.
• 😀 In a scenario with three parallel wires carrying different currents, the total force on the middle wire is the result of the forces from both neighboring wires, with directions determined by whether the currents are parallel or opposing.

Q & A

What is the Lorentz force on a current-carrying wire?

The Lorentz force on a current-carrying wire is the force experienced by the wire due to the interaction between the current flowing through the wire and the magnetic field it is placed in. The force is given by the formula FL = BIL sin(α), where FL is the Lorentz force, B is the magnetic field, I is the current, L is the length of the wire, and α is the angle between the magnetic field and the current.

What is the formula for calculating the magnitude of the Lorentz force?

The formula for calculating the magnitude of the Lorentz force on a current-carrying wire is FL = BIL sin(α), where FL is the Lorentz force, B is the magnetic field strength (measured in Tesla), I is the electric current (measured in amperes), L is the length of the wire (measured in meters), and α is the angle between the magnetic field and the current direction.

How do we determine the direction of the Lorentz force?

The direction of the Lorentz force can be determined using the right-hand rule. You extend your right hand, with your thumb pointing in the direction of the current (I), your fingers pointing in the direction of the magnetic field (B), and the direction your palm pushes will give the direction of the force (F).

What happens when two current-carrying wires are parallel and carry current in the same direction?

When two current-carrying wires are parallel and carry current in the same direction, they exert an attractive force on each other. This is a result of the magnetic field created by each wire interacting with the current in the other wire.

How does the direction of current affect the force between two wires?

The direction of the current affects whether the force between two wires is attractive or repulsive. If the currents flow in the same direction, the force is attractive, whereas if the currents flow in opposite directions, the force is repulsive.

What is the formula for the force per unit length between two parallel current-carrying wires?

The formula for the force per unit length between two parallel current-carrying wires is given by: F/L = (μ₀ / 2π) * (I₁ * I₂ / d), where F/L is the force per unit length, μ₀ is the permeability of free space (4π x 10⁻⁷ T·m/A), I₁ and I₂ are the currents in the two wires, and d is the distance between the wires.

What happens when the currents in two wires are opposite in direction?

When the currents in two parallel wires are opposite in direction, the force between them is repulsive. This means the wires push away from each other, as the magnetic fields generated by each wire oppose each other.

How do you calculate the Lorentz force on a wire placed in a magnetic field?

To calculate the Lorentz force on a wire in a magnetic field, use the formula FL = BIL sin(α). You need to know the strength of the magnetic field (B), the current (I), the length of the wire (L), and the angle (α) between the magnetic field and the direction of the current.

In the example problem, what is the Lorentz force on a 2-meter long wire carrying a 50-ampere current placed in a 0.03-Tesla magnetic field at a 30° angle?

Using the formula FL = BIL sin(α), the Lorentz force is calculated as follows: FL = 0.03 T * 50 A * 2 m * sin(30°). This results in a Lorentz force of 1.5 N.

What is the relationship between the distance between two wires and the force they exert on each other?

The force between two parallel current-carrying wires is inversely proportional to the distance between them. As the distance increases, the force decreases. This relationship is captured in the formula F/L = (μ₀ / 2π) * (I₁ * I₂ / d), where d is the distance between the wires.