Concept #1: Electromagnetic Waves as Sinusoidal Waves

At an instant of time and at a particular location in space, the electric field of an electromagnetic wave is in the -x-direction and the magnetic field is in the +y-direction. What is the direction in which the wave is traveling?
A) +x
B) -x
C) +y
D) -y
E) +z
F) -z

An electromagnetic wave propagates through a vacuum in the +x-direction, carrying an intensity of 150 W/m2. At t = 0, the electric field has zero amplitude, and after 0.01 s, the electric field strength grows to its maximum value, pointing in the +y direction. Write equations describing the electric and magnetic fields as sinusoidal oscillations, including the appropriate unit vectors to denote direction.

At a certain instant in time, an electromagnetic wave has Ē in the +z direction and B in the +y direction. In what direction does the wave propagate?A) -x directionB) +x directionC) +y directionD) -z directionE) +z direction

The y component of the electric field of an electromagnetic wave travelling in the +x direction through vacuum obeys the equation Ey = (375 N/C) cos [kx − (2.20 × 10 14 rad/s)t]. What is the wavelength of this electromagnetic wave?
a. 0.272 μm
b. 1.36 μm
c. 2.72 μm
d. 8.57 μm
e. 17.1 μm

The magnetic field of a plane EM wave is given by: B = (E0/c) sin(kz + ωt) i The electric field of the wave would be given by:A. E = +E0 sin(kz + ωt) jB. E = +E0 cos(kz + ωt) kC. E = +E0 cos(kz + ωt) jD. E = –E0 cos(kz + ωt) iE. E = –E0 cos(kz + ωt) i

A sinusoidal electromagnetic wave propogates in the -y direction in a medium with a refractive index of 1.5, with a magnetic field amplitude of 0.001 T and a wavelength of 1.55 nm.
(a) What is the angular frequency of the wave?
(b) What is the electric field amplitude of the wave?
(c) What is the intensity of the wave?