Gaya pada Kawat Sejajar | Medan Magnet | Part 3 | Fisika Dasar

Summary

This video lesson delves into the concept of magnetic force between parallel wires carrying current. It explains how wires exert attractive or repulsive forces depending on the direction of the currents. The interaction is illustrated through the Lorentz force, showing how one wire generates a magnetic field that influences another. A practical example with four wires is provided to demonstrate how to calculate the required current and direction in one wire so that it experiences no net force. The video explains these concepts clearly, using a step-by-step approach to solving the problem and making it accessible for learners.

Takeaways

• 😀 The interaction between parallel current-carrying wires can either be attractive or repulsive, depending on the direction of the currents.
• 😀 When two wires have currents in the same direction, they exert an attractive force on each other.
• 😀 When the currents in the two wires are in opposite directions, the wires exert a repulsive force on each other.
• 😀 The force between two parallel wires carrying currents is calculated per unit length, assuming the wires are infinitely long.
• 😀 The force on a wire is proportional to the product of the currents and inversely proportional to the distance between the wires.
• 😀 The magnetic field generated by a current-carrying wire affects the other wires nearby, creating a force due to the magnetic interaction.
• 😀 The right-hand rule is used to determine the direction of the magnetic field and force between current-carrying wires.
• 😀 The interaction between the wires can be understood through the Lorentz force, which relates magnetic fields to forces on charged particles.
• 😀 In practical problems, such as with four parallel wires, the direction and magnitude of currents must be adjusted to balance the forces on a wire.
• 😀 A sample problem demonstrated the process of finding the correct current in one wire to ensure no net force on another wire, resulting in the correct current of 4.5 A in the fourth wire.

Q & A

What happens when two parallel wires carry currents in the same direction?

When two parallel wires carry currents in the same direction, they attract each other. This is because the magnetic fields generated by the wires interact in a way that pulls the wires together.

What happens when two parallel wires carry currents in opposite directions?

When the currents in two parallel wires are in opposite directions, the wires repel each other. This occurs because the magnetic fields around each wire interact to push the wires apart.

How is the direction of the magnetic field around a current-carrying wire determined?

The direction of the magnetic field around a current-carrying wire can be determined using the right-hand rule. By pointing the thumb of your right hand in the direction of the current, the curl of your fingers will show the direction of the magnetic field.

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 I₁ I₂) / (2π R), where μ₀ is the permeability of free space, I₁ and I₂ are the currents in the wires, and R is the distance between the wires.

Why is the formula for force per unit length used instead of the total force between the wires?

The formula for force per unit length is used because the wires are assumed to be infinitely long, making it impractical to calculate the total force. Instead, the force per unit length allows for a simplified and consistent way to calculate the force between the wires regardless of their length.

How does the magnetic field from one wire affect the other wire?

The magnetic field generated by one wire exerts a force on the other wire. If the currents are in the same direction, the force is attractive; if the currents are in opposite directions, the force is repulsive. This interaction is what causes the wires to either attract or repel each other.

What is the concept of Lorentz force and how does it relate to this scenario?

The Lorentz force is the force on a charged particle due to both electric and magnetic fields. In the case of current-carrying wires, the moving charges in the wires experience a Lorentz force because of the magnetic field produced by the other wire.

In the example with four parallel wires, what is the goal of the problem?

The goal of the problem is to find the current direction in the fourth wire such that the net force on the first wire is zero. This involves calculating the forces between each pair of wires and solving for the unknown current in the fourth wire.

How are the forces between the wires calculated in the example problem?

The forces between the wires are calculated using the formula for force per unit length. The forces are then summed, and the required current for the fourth wire is determined to ensure the net force on the first wire is zero.

What is the significance of solving for the current in the fourth wire in the example?

Solving for the current in the fourth wire ensures that the net force on the first wire is zero, which is the condition given in the problem. This demonstrates how the interaction of currents and magnetic fields can be balanced in a system of parallel wires.