of the following statements: I. In a vacuum, electromagnetic waves travel at the speed of light. The magnitudes of electric field and magnetic field are equal. II. III. Both the magnetic field vector and the electric field vector are perpendicular to the Poynting vector. IV. The electric field vector and magnetic field vector are parallel. Which are true? a) II y III b) ly Ill c) III y IV d) I y IV

of the following statements: I. In a vacuum, electromagnetic waves travel at the speed of light. The magnitudes of electric field and magnetic field are equal. II. III. Both the magnetic field vector and the electric field vector are perpendicular to the Poynting vector. IV. The electric field vector and magnetic field vector are parallel. Which are true? a) II y III b) ly Ill c) III y IV d) I y IV

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter24: Electromagnetic Waves

Section: Chapter Questions

Problem 22P

See similar textbooks

Similar questions

Consider an electromagnetic wave traveling in the positive y direction. The magnetic field associated with the wave at some location at some instant points in the negative x direction as shown in Figure OQ24.12. What is the direction of the electric field at this position and at this instant? (a) the positive x direction (b) the positive y direction (c) the positive z direction (d) the negative z direction (e) the negative y direction Figure OQ24.12
Radio waves normally have their E and B fields in specific directions, whereas visible light usually has its E and B fields in random and rapidly changing directions that are perpendicular to each other and to the propagation direction. Can you explain why?
A dish antenna having a diameter of 20.0 m receives (at normal incidence) a radio signal from a distant source as shown in Figure P24.63. The radio signal is a continuous sinusoidal wave with amplitude Emax = 0.200 V/m. Assume the antenna absorbs all the radiation that falls on the dish. (a) What is the amplitude of the magnetic field in this wave? (b) What is the intensity of the radiation received by this antenna? (c) What is the power received by the antenna? (d) What force is exerted by the radio waves on the antenna? Figure P24.63
Figure P34.15 shows a plane electromagnetic sinusoidal wave propagating in the x direction. Suppose the wavelength is 50.0 m and the electric field vibrates in the xy plane with an amplitude of 22.0 V/m. Calculate (a) the frequency of the wave and (b) the magnetic field B when the electric field has its maximum value in the negative y direction, (c) Write an expression for B with the correct unit vector, with numerical values for Bmax, k, and , and with its magnitude in the form
A spherical interplanetary grain of dust of radius 0.2 m is at a distance r1 from the Sun. The gravitational force exerted by the Sun on the grain just balances the force due to radiation pressure from the Sun's light. (i) Assume the grain is moved to a distance 2r1 from the Sun and released. At this location, what is the net force exerted on the grain? (a) toward the Sun (b) away from the Sun (c) zero (d) impossible to determine without knowing the mass of the grain (ii) Now assume the grain is moved back to its original location at r1, compressed so that it crystallizes into a sphere with significantly higher density, and then released. In this situation, what is the net force exerted on the grain? Choose from the same possibilities as in part (i).
If the electric field of an electromagnetic wave is oscillating along the z-axis and the magnetic field is oscillating along the x-axis, in what possible direction is the wave traveling?