Is charge moving?.

Slides:



Advertisements
Similar presentations
Electromagnetic Waves (Optional Unit)
Advertisements

Chapter 32C - Electromagnetic Waves (Optional Unit)
29. Maxwell’s Equations. 2 Topics Laws of Electric & Magnetic Fields James Clerk Maxwell Maxwell’s Equations.
Maxwell’s Equations and Electromagnetic Waves
Maxwell’s Equations and Electromagnetic Waves
© 2005 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching their.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Chapter 35. Electromagnetic Fields and Waves To understand a laser beam,
Chapter 22 Electromagnetic Waves. Units of Chapter 22 Changing Electric Fields Produce Magnetic Fields; Maxwell’s Equations Production of Electromagnetic.
Two questions: (1) How to find the force, F on the electric charge, Q excreted by the field E and/or B? (2) How fields E and/or B can be created? Gauss’s.
© 2012 Pearson Education, Inc. { Chapter 31 Alternating Current Circuits (cont.)
Electromagnetic Waves
Announcements  EXAM 3 is scheduled for Thursday, April 16!  Homework for tomorrow… Ch. 34: Probs. 12, 17, 20, & 22 CQ4: a) CWb) no currentc) CCW 33.10:
Happyphysics.com Physics Lecture Resources Prof. Mineesh Gulati Head-Physics Wing Happy Model Hr. Sec. School, Udhampur, J&K Website: happyphysics.com.
Lecture 13 Electromagnetic Waves Ch. 33 Cartoon Opening Demo Topics –Electromagnetic waves –Traveling E/M wave - Induced electric and induced magnetic.
Chapter 23 Electromagnetic Waves. Formed from an electric field and magnetic field orthonormal to each other, propagating at the speed of light (in a.
p.1067 Ch 34 Electromagnetic Waves 34.1 Displacement Current and the General Form of Ampere’s Law I d =  0 d  E /dt B·ds =  0 (I + I d ) 
Physics 1402: Lecture 26 Today’s Agenda Announcements: Midterm 2: NOT Nov. 6 –About Monday Nov. 16 … Homework 07: due Friday this weekHomework 07: due.
Homework set #3 is posted Due Tuesday by 5PM No late homework accepted Homework set #4 is posted Due Tuesday September 29 th by 5PM Same day as Exam I.
Chapter 33 Electromagnetic Waves
Electromagnetic Waves Electromagnetic waves are identical to mechanical waves with the exception that they do not require a medium for transmission.
Electromagnetic Waves.  Concept and Nature of EM Waves  Frequency, Wavelength, Speed  Energy Transport  Doppler Effect  Polarization.
Chapter 33. Electromagnetic Waves What is Physics? Maxwell's Rainbow The Traveling Electromagnetic Wave, Qualitatively The Traveling.
Announcements EXAM 3 is THIS Thursday! Homework for tomorrow…
Electromagnetic Waves. Maxwell’s Rainbow: The scale is open-ended; the wavelengths/frequencies of electromagnetic waves have no inherent upper or lower.
Four equations (integral form) : Gauss’s law Gauss’s law for magnetism Faraday’s law Ampere-Maxwell law + Lorentz force Maxwell’s Equations.
Lecture 21-1 Resonance For given  peak, R, L, and C, the current amplitude I peak will be at the maximum when the impedance Z is at the minimum. Resonance.
Electromagnetic Waves
Chapter 21 Electromagnetic Waves. General Physics Exam II Curve: +30.
APHY201 10/24/ Maxwell’s Equations   1865 – James Maxwell unifies electricity and magnetism and shows that their fields move through space.
Copyright © 2012 Pearson Education Inc. PowerPoint ® Lectures for University Physics, Thirteenth Edition – Hugh D. Young and Roger A. Freedman Lectures.
Chapter 33 Electromagnetic Waves. 33.2: Maxwell’s Rainbow: As the figure shows, we now know a wide spectrum (or range) of electromagnetic waves: Maxwell’s.
Chapter 34 (continued) The Laws of Electromagnetism Maxwell’s Equations Displacement Current Electromagnetic Radiation.
1 30 Outline Maxwell’s Equations and the Displacement Current Electromagnetic Waves Polarization.
Electromagnetic Waves
Copyright © 2009 Pearson Education, Inc. Energy in EM Waves: The Poynting Vector.
Final Exam Lectures EM Waves and Optics. Electromagnetic Spectrum.
Lecture 21-1 Maxwell’s Equations (so far) Gauss’s law Gauss’ law for magnetism Faraday’s lawAmpere’s law *
1 30 Outline Maxwell’s Equations and the Displacement Current Electromagnetic Waves Polarization.
Announcements EXAM 3 will be this Thursday!
Electromagnetic Waves
Two questions: (1) How to find the force, F on the electric charge, Q excreted by the field E and/or B? (2) How fields E and/or B can be created?
Electromagnetic Waves
Electromagnetic Waves
Electromagnetic Waves
Electromagnetic Waves
E or B? It Depends on Your Perspective
Physics: Principles with Applications, 6th edition
Maxwell’s Equations and Electromagnetic Waves
Electromagnetic Waves
Lecture 14 : Electromagnetic Waves
The equations so far..... Gauss’ Law for E Fields
Chapter 33. Electromagnetic Waves
Maxwell’s Equations and Electromagnetic Waves
Electromagnetic Waves
Chapter 31 Electromagnetic Fields and Waves
Figure Two surfaces S1 and S2 near the plate of a capacitor are bounded by the same path P. The conduction current in the wire passes only through.
Electromagnetic Waves
Scattering by free charges
PHYS 221 Recitation Kevin Ralphs Week 9.
Maxwell’s Equations and Electromagnetic Waves
Physics: Principles with Applications, 6th edition
Two questions: (1) How to find the force, F on the electric charge, Q excreted by the field E and/or B? (2) How fields E and/or B can be created?
Electromagnetic Waves
29. Maxwell’s Equations & Electromagnetic Waves
Maxwell’s Equations (so far)
Electromagnetic Waves
Chapter 33 Electromagnetic Waves
Polarization Light travels as a transverse wave, with the electric and magnetic fields oscillating perpendicular to the forward motion of the wave Light.
Electromagnetic Waves
Chapter 22 Electromagnetic Waves
Presentation transcript:

Is charge moving?

Bills Observation: magnetic force

Sharon’s Observation: no magnetic force Charge isn’t moving, so B can’t act on q to create a force

E or B?

E or B? It Depends on Your Perspective

E or B? It Depends on Your Perspective Whether a field is seen as “electric” or “magnetic” depends on the motion of the reference frame relative to the sources of the field.

E or B? It Depends on Your Perspective The Galilean field transformation equations are where V is the velocity of frame S' relative to frame S and where the fields are measured at the same point in space by experimenters at rest in each reference frame. NOTE: These equations are only valid if V << c.

Ampère’s law Whenever total current Ithrough passes through an area bounded by a closed curve, the line integral of the magnetic field around the curve is The figure illustrates the geometry of Ampère’s law. In this case, Ithrough = I1 − I2 .

The Displacement Current The electric flux due to a constant electric field E perpendicular to a surface area A is The displacement current is defined as Maxwell modified Ampère’s law to read

Maxwell’s Equations

Electromagnetic Waves Maxwell, using his equations of the electromagnetic field, was the first to understand that light is an oscillation of the electromagnetic field. Maxwell was able to predict that Electromagnetic waves can exist at any frequency, not    just at the frequencies of visible light. This prediction    was the harbinger of radio waves. All electromagnetic waves travel in a vacuum with the    same speed, a speed that we now call the speed of    light.

Properties of Electromagnetic Waves Any electromagnetic wave must satisfy four basic conditions: The fields E and B and are perpendicular to the direction of propagation vem.Thus an electromagnetic wave is a transverse wave. E and B are perpendicular to each other in a manner such that E × B is in the direction of vem.  The wave travels in vacuum at speed vem = c  E = cB at any point on the wave.

Properties of Electromagnetic Waves The energy flow of an electromagnetic wave is described by the Poynting vector defined as The magnitude of the Poynting vector is The intensity of an electromagnetic wave whose electric field amplitude is E0 is

Radiation Pressure It’s interesting to consider the force of an electromagnetic wave exerted on an object per unit area, which is called the radiation pressure prad. The radiation pressure on an object that absorbs all the light is where I is the intensity of the light wave. The subscript on prad is important in this context to distinguish the radiation pressure from the momentum p.

Malus’s Law Suppose a polarized light wave of intensity I0 approaches a polarizing filter. θ is the angle between the incident plane of polarization and the polarizer axis. The transmitted intensity is given by Malus’s Law: If the light incident on a polarizing filter is unpolarized, the transmitted intensity is In other words, a polarizing filter passes 50% of unpolarized light and blocks 50%.