Back(II) Pulsed lasers used for science and medicine produce very brief bursts of electromagnetic energy. If the laser light wavelength is 1062 mm (Neodymium–YAG laser), and the pulse lasts for 32 picoseconds, how many wavelengths are found within the laser pulse? How brief would the pulse need to be to fit only one wavelength?
(I) The field in an EM wave has a peak of 23.5 mV/m. What is the average rate at which this wave carries energy across unit area per unit time?
(II) The magnetic field in a traveling EM wave has an rms strength of 22.5 nT. How long does it take to deliver 415 J of energy to 1.00 cm2 of a wall that it hits perpendicularly?
(II) Estimate the average power output of the Sun, given that about 1350 W/m2 reaches the upper atmosphere of the Earth.
(II) What size should the solar panel on a satellite orbiting Jupiter be if it is to collect the same amount of radiation from the Sun as a 1.0-m2 solar panel on a satellite orbiting Earth? [Hint: Assume the inverse square law.]
What are E0 and B0 at a point 2.50 m from a light source whose output is 5.0 W? Assume the bulb emits radiation of a single frequency uniformly in all directions.
What is the average energy contained in a 1.00-m3 volume near the Earth’s surface due to radiant energy from the Sun? See Example 31–6.
How long does it take light to reach us from the Sun, 1.50 x 108 km away?
A scientist measures a 3.00-mV rms voltage across a 1.50-m-long sensor that is aligned with the electric field of an electromagnetic wave. What is the electric field strength and the corresponding rate of energy transport per m2?
Show that displacement current, ε₀ (dΦE/dt), has the SI units of amperes.
If a galaxy is traveling away from us at 2.2% of the speed of light, roughly how far away is it?
Suppose a 25-kW radio station emits EM waves uniformly in all directions. How much energy per second crosses a 1.0-m2 area 1.0 km from the transmitting antenna?
When estimating the distance to lightning, you can time how long after the light flash is seen until the thunder is heard. Sound travels 343 m/s, so a good estimate is to allow 3.0 seconds per kilometer. There is actually a small mistake with this method because the time for the light to travel is not accounted for. How big is this mistake (%) for a lightning flash 2.0 km away?
The average intensity of a particular TV station’s signal is 1.0 x 10-13 W/m2 when it arrives at a 33-cm-diameter satellite TV antenna. (a) Calculate the total energy received by the antenna during 3.0 hours of viewing this station’s programs. (b) Estimate the amplitudes of the E and B fields of the EM wave.
The nearest neighboring star to the Sun is about 4 light-years away. If a planet happened to be orbiting this star at an orbital radius equal to that of the Earth–Sun distance, what minimum diameter would an Earth-based telescope’s aperture have to be in order to obtain an image that resolved this star–planet system? Assume the light emitted by the star and planet has a wavelength of 550 nm.