The owl has good night vision because its eye can detect an average light intensity as small as 3.0 10-13 W/m2for light with wavelength of 550 nm. (a) What is the rms value of the electric field of light with this intensity? (b) What is the peak value of the magnetic field of light with this intensity?

The owl has good night vision because its eye can detect an average light intensity as small as 3.0 10-13 W/m2for light with wavelength of 550 nm. (a) What is the rms value of the electric field of light with this intensity? (b) What is the peak value of the magnetic field of light with this intensity?

University Physics Volume 2

18th Edition

ISBN:9781938168161

Author:OpenStax

Publisher:OpenStax

Chapter16: Electromagnetic Waves

Section: Chapter Questions

Problem 42P: What is the maximum electric field strength in an electromagnetic wave that has a maximum magnetic...

See similar textbooks

Similar questions

A plane electromagnetic wave travels northward. At one instant, its electric field has a magnitude of 6.0 V/m and points eastward. What are the magnitude and direction of the magnetic field at this instant?
An automobile with a radio antenna 1.0 m long travels at 100.0 km/h in a location where theEarth’s horizontal magnetic field is 5.5105T . What is the maximum possible emf induced in the antenna due to this motion?
A parallel-plate capacitor with plate separation d is connected to a source of emf that places a time-dependent voltage V(t) across its circular plates of radius r0and area (a) Write an expression for the time rate of change of energy inside the capacitor in terms of V(t) and dV(t)/ dt. (b) Assuming that V(t) is increasing with time, identify the directions of the elecuic field lines inside the capacitor and of the magnetic field lines at the edge of the region between the plates, and then the direction of the Poynting vector S at this location. (c) Obtain expressions for the time dependence of E(t), for B(t) from the displacement current, and for the magnitude of the Poynting vector at the edge of the region between the plates. (d) From S , obtain an expression In terms of ‘(t) and dV(t)/dt for the rate at which electromagnetic field energy the region between the plates. (e) Compare the results of pails (a) and (d) and explain the relationship between them.
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?
An incandescent light bulb emits only 2.6 W of its power as visible light. What is the rms electric field of the emitted light at a distance of 3.0 m from the bulb?
A radio transmitter broadcasts plane electromagnetic waves whose maximum electric field at a particular location is 1.55103V/m . What is the maximum magnitude of the oscillating magnetic field at that location? How does it compare with Earth’s magnetic field?
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?
On its highest power setting, a microwave oven increases the temperature of 0.400 kg of spaghetti by 45.0°C in 120 s. (a) What was the rate of energy absorption by the spaghetti, given that its specific heat is 3.76103J/kg.C ? Assume the spaghetti is perfectly absorbing. (b) Find the average intensity of the microwaves, given that they are absorbed over a circular area 20.0 cm in diameter. (C) What is the peak electric field strength of the microwave? (d) What is its peak magnetic field strength?
What is the maximum electric field strength in an electromagnetic wave that has a maximum magnetic field strength of 5.00104 (about 10 times Earth's magnetic field)?
Suppose the magnetic field of an electromagnetic wave is given by B = (1.5 1010) sin (kx t) T. a. What is the maximum energy density of the magnetic field of this wave? b. What is maximum energy density of the electric field?
Suppose the maximum safe intensity of microwaves for human exposure is taken to be 1,00 W/m2. (a) If a radar unit leaks 10.0 W of microwaves (other than those sent by its antenna) uniformly in all directions, how far away must you be to be exposed to an intensity considered to be safe? Assume that the power spreads uniformly over the area of a sphere with no complications from absorption or reflection, (b) What is the maximum electric field strength at the safe intensity? (Note that early radar units leaked more than modem ones do. This caused identifiable health problems, such as cataracts, for people who worked near them.)
Can the human body detect electromagnetic radiation that is outside the visible region of the spectrum?