* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Session 26 - Iowa State University
Superconductivity wikipedia , lookup
Electromagnet wikipedia , lookup
Maxwell's equations wikipedia , lookup
Speed of gravity wikipedia , lookup
Electrostatics wikipedia , lookup
Lorentz force wikipedia , lookup
Coherence (physics) wikipedia , lookup
Field (physics) wikipedia , lookup
Time in physics wikipedia , lookup
Circular dichroism wikipedia , lookup
Introduction to gauge theory wikipedia , lookup
Diffraction wikipedia , lookup
Photon polarization wikipedia , lookup
Thomas Young (scientist) wikipedia , lookup
Electromagnetism wikipedia , lookup
Aharonov–Bohm effect wikipedia , lookup
Electromagnetic radiation wikipedia , lookup
Wave–particle duality wikipedia , lookup
Wave packet wikipedia , lookup
Theoretical and experimental justification for the Schrödinger equation wikipedia , lookup
Session 26: EM Waves Supplemental Instruction Iowa State University Leader: Course: Instructor: Date: Garrett Schieber Phys 222 Dr. Al-Saqer 11/10/14 Warm up: 1) The electric and magnetic fields in a traveling plane electromagnetic wave in vacuum at a ⃗ , respectively. The particular point in space and at a particular instant of time are 𝐸⃗ and 𝐵 direction of propagation of the wave is in the direction of ____ . a) 𝐸⃗ ⃗ b) 𝐵 ⃗ × 𝐸⃗ c) 𝐵 ⃗ × ⃗𝑩 ⃗ d) ⃗𝑬 ⃗ e) 𝐸⃗ ∙ 𝐵 2) An electromagnetic plane wave in vacuum is moving in the + y direction. At time t = 0 and at position (x,y,z) = (0,0,0), the electric field is pointing in the + z direction. At that time and position, the magnetic field in the wave is pointed in the ____ direction. a) +x b) +y c) +z d) –x e) –z Group Activity 3) The electric field of a sinusoidal electromagnetic wave obeys the equation: (Book 32.8) a) What is the amplitude of the electric field of this wave? b) What is the amplitude of the magnetic field of this wave? c) What is the frequency of the wave? d) What is the wavelength of the wave? e) What is the period of the wave? f) Is this light visible to humans? g) What is the speed of the wave? Supplemental Instruction 1060 Hixson-Lied Student Success Center 294-6624 www.si.iastate.edu 4) The microwaves in a certain microwave oven have a wavelength of 12.2 cm. (Book 32.35) a) How wide must this oven be so that it will contain five antinodal planes of the electric field along its width in the standing wave pattern? b) What is the frequency of these microwaves? c) Suppose a manufacturing error occurred and the oven was made 6.0 cm longer than specified in part (a). In this case, what would have to be the frequency of the microwaves for there still to be five antinodal planes of the electric field along the width of the oven? 5) We can reasonably model a 90-W incandescent light bulb as a sphere 6.1 cm in diameter. Typically, only about 5% of the energy goes to visible light; the rest goes largely to nonvisible infrared radiation. (Book 32.15) a) What is the visible light intensity at the surface of the bulb? b) What is the amplitude of the electric field at this surface, for a sinusoidal wave with this intensity? c) What is the amplitude of the magnetic field at this surface, for a sinusoidal wave with this intensity?