Two Parallel Wires

Part of the Electricity and Magnetism section of Coddy's Physics journey. Lesson 45 of 51.

Parallel currents the same way attract; opposite ways, they repel:

$F = \frac{\mu_0 I_1 I_2 L}{2\pi d}$

Two parallel wires

Both wires feel the same size of force.

Challenge

Two long parallel wires $10\ \mathrm{cm}$ apart each carry $10\ \mathrm{A}$ to the right. Draw the magnetic force the upper wire puts on the lower one, then find how big it is, $F$ , on a $2\ \mathrm{m}$ length of the lower wire.

Try it yourself

Solve for $F$

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Electricity and Magnetism

1Electric Charge and Force

Electric Charge Coulomb's Law Several Charges Recap - Charges in a Line

4Charged Conductors

The Charged Sphere Connecting Spheres Recap - Beam Between Plates

7Real Batteries

Internal Resistance The Variable Resistor Ammeters and Voltmeters Recap - Flashlight

10Magnetic Fields

Magnets and Magnetic Fields Field of a Wire Loops and Solenoids Recap - Electromagnet

2The Electric Field

The Electric Field Field of Several Charges The Uniform Field A Charge in a Uniform Field Recap - Stopping a Proton

5Capacitors

The Capacitor Combining Capacitors Changing a Capacitor Recap - Camera Flash

8Kirchhoff's Laws

The Junction Rule The Loop Rule Solving Two Loops Recap - Charging a Battery

11Magnetic Forces

Force on a Moving Charge Circles in a Field Force on a WireTwo Parallel WiresRecap - Current Balance

3Energy and Potential

Electric Potential Energy Electric Potential Field and Potential Recap - Accelerating Ions

6Current and Resistance

Current and Voltage Resistance and Ohm's Law Series and Parallel Electric Power Recap - Fairy Lights

9Capacitors in Circuits

A Capacitor in a Circuit Charging a Capacitor Discharging a Capacitor Recap - Defibrillator

12Induction

A Rod Moving in a Field Magnetic Flux Faraday's Law Lenz's Law Recap - Generator