The time-averaged intensity of a wave of visible light propagating in a vacuum is 1,800 watts/m2. What is the maximum value of the electric field for this wave?   a. 2,080 N/C   b. 1,160 N/C   c. 1,500 N/C   d. 1,750 N/C   e. 1,320 N/C

A beam of light passes from air into fused quartz. Which of the following is true about the electromagnetic wave as it passes into the new medium? Material Fluorite Fused Quartz Sapphire Diamond ... Index of Refraction 1.40 1.50 1.79 2.42 A) Wavelength stays constant, frequency and speed decrease B) Speed stays constant, frequency increases, wavelength decreases C Frequency stays constant, speed decreases, wavelength increases D Frequency stays constant, speed and wavelength decrease

19. A laser uniformly illuminates an area with green light that has an average intensity of 550 W/m2. What is the rms value of the electric field of this light? A) 322 N/C B) 405 N/C C) 455 N/C D) 643 N/C E) 891 N/C Ans: C

Which of the following correctly orders electromagnetic waves by increasing frequency? a. radio, visible, infrared, x-ray   b. infrared, ultraviolet, visible, gamma   c. visible, infrared, ultraviolet, x-ray   d. infrared, visible, x-ray, gamma

Problem 5. Assume that electromagnetic propagation through space is what we have been calling "free space." b) How long does it take to communicate with electromagnetic waves from Mars to Earth? Another way of asking this question is how long does it take for an electromagnetic signal originating on Mars to reach Earth? c) for two humans separated by 6 feet, how long does it take for the light reflected off of one person to be seen by the other person?

4. What is the intensity of an electromagnetic wave with a peak electric field strength of 110 V/m?     This is not and will not be graded

www WiFi (microwaves) waves travel 100m in the x-direction from a transmitter to a computer. The maximum electric field at the computer is 77.5mV/m and points in the z-direction. The frequency of the WiFi system is 2.4GHz. a. At the computer, the magnetic field points in what direction? b. At the computer, what is magnitude of the maximum magnetic field? c. How much power is being transmitted by the WiFi transmitter? d. wwwmm How much time does it take for waves to travel from the WiFi transmitter to the computer?

An observer at a fixed distance from a light bulb measures the light intensity at her location to be 10 watts/m2. What is the maximum value of the electric field strength at the observer's location?    a. 87 N/C   b. 61 N/C   c. 48 N/C   d. 74 N/C   e. 100 N/C

The average intensity a distance d₁ = 1.6 m from an omni-directional light bulb is l₁ = 1.3 W/m². (a) Write a symbolic expression for the intensity a distance d₂ = 2.5 m from the same bulb, in terms of ₁, d₁ and d₂, and calculate its numeric value. 1, ₂ W/m² (Don't worry about the font -- use 11 for 1.) (b) Calculate the maximum output power of the light bulb. Pmax = W