Lecture 20 – Forces on Currents

26.6 Magnetic Forces on Current Carrying Conductors

Magnetic Fields Exert Forces on Currents

Fwire ILBMagnitude of the force on a current segment of length L perpendicular to a magnetic field

Slide 24-37

Forces between Currents

Fparallel wires 0LI1I2

2d

Slide 24-38

Magnetic force between two parallel current-carrying wires

Forces between Current Loops

Slide 24-40

A Current Loop Acts like a Bar Magnet

Slide 24-41

Homework due today

• Problems 24: CQ10, MC33, 22, 25, 26, 29, 31, WB 24: 16-22

• Due Wednesday: Read 24: 7-8 Magnetic forces on magnetic dipoles and MRI

• Problems: 24: 32, 34, 37

Magnetic Fields Exert Torques on Current Loops

Slide 24-42

The Torque on a Dipole in a Magnetic Field

IA B sin

Slide 24-43