Exam 24: Electromagnetic Waves

Two identical silver spheres of mass m and radius r are placed a distance R (sphere 1)and 2R (sphere 2)from the sun respectively.The ratio of the gravitational force exerted by the sun on sphere 1 to the pressure of solar radiation on sphere 1 is T₁;the ratio for sphere 2 is T₂.The ratio of T₂ to T₁ is

The sun radiates energy at a rate of 3.86 *10²⁶ W.Its radius is 7.0 * 10⁸ m.If the distance from the Earth to the sun is 1.5 * 10¹¹ m,what is the intensity of solar radiation at the top of the Earth's atmosphere?

A spherical particle of density $\rho = 5.00 \frac { \mathrm { g } } { \mathrm { cm } ^ { 2 } }$ and 2.00 mm radius is located at the same distance from the Sun as the Earth. R_SE = 1.5* 10¹¹ m, $G = 6.67 \times 10 ^ { - 11 } \frac { \mathrm { Nm } ^ { 2 } } { \mathrm {~kg} ^ { 2 } } , S = 1365 \frac { \mathrm { W } } { \mathrm { m } ^ { 2 } } , M _ { S } = 1.99 \times 10 ^ { 30 } \mathrm {~kg}$ . If the particle absorbs 100 percent of the sunlight reaching it,the ratio of the force exerted by the solar radiation to the force of gravity exerted on the particle by the Sun is

In an electromagnetic wave,1)how are the electric and magnetic field directions related and 2)how is the direction of travel determined from their directions? ( $\overrightarrow { \mathbf { c } }$ is the velocity of the light wave. )

The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by $B = 1.2 \times 10 ^ { - 6 } \sin \left[ 2 \pi \left( \frac { z } { 240 } - \frac { t \times 10 ^ { 7 } } { 8 } \right) \right]$ in SI units.What is the frequency of the wave?

What should be the height of a dipole antenna (of dimensions 1/4 wavelength)if it is to transmit 1 200 kHz radiowaves?

How much electromagnetic energy is contained in each cubic meter near the Earth's surface if the intensity of sunlight under clear skies is 1 000 W/m²?

At every instant the ratio of the magnitude of the electric to the magnetic field in an electromagnetic wave in vacuum is equal to

In the atmosphere,the shortest wavelength electromagnetic waves are called

What is the maximum radiation pressure exerted by sunlight in space (S = 1 350 W/m²)on a flat black surface?

Find the force exerted by reflecting sunlight off a reflecting aluminum sheet in space if the area normal to the sunlight is 10 000 m² and the solar intensity is 1 350 W/m².

A possible means of spaceflight is to place a perfectly reflecting aluminized sheet into Earth orbit and use the light from the sun to push this solar sail.If a huge sail of area 6.00 *10⁵ m² and mass 6 000 kg were placed into orbit and turned toward the sun,what would be the force exerted on the sail? (Assume a solar intensity of 1 380 W/m². )

The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by $B = 1.2 \times 10 ^ { - 6 } \sin \left[ 2 \pi \left( \frac { z } { 240 } - \frac { t \times 10 ^ { 7 } } { 8 } \right) \right]$ in SI units.Find the average power per square meter carried by the EM wave.

At a distance of 10 km from a radio transmitter,the amplitude of the E-field is 0.20 volts/meter.What is the total power emitted by the radio transmitter?

Scattered light in the atmosphere is often partially polarized.The best way to determine whether or not light from a particular direction in the sky shows polarization is to

The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by $B = 1.2 \times 10 ^ { - 6 } \sin \left[ 2 \pi \left( \frac { z } { 240 } - \frac { t \times 10 ^ { 7 } } { 8 } \right) \right]$ in SI units.What is the maximum E-field?

If the radiant energy from the sun comes in as a plane EM wave of intensity 1 340 W/m²,calculate the peak values of E and B.

A solar cell has a light-gathering area of 10 cm² and produces 0.2 A at 0.8 V (DC)when illuminated with S = 1 000 W/m² sunlight.What is the efficiency of the solar cell?

What is the average value of the magnitude of the Poynting vector $\vec { S }$ at 1 meter from a 100-watt lightbulb radiating in all directions?

Polarized light is to have its polarization plane rotated by 90 $\degree$ .In which of the following cases does the final beam have the greatest intensity?