1. The Earth is {image} meters from the sun
The Earth is {image} meters from the sun. If the solar radiation at the top of the Earth's atmosphere is {image} what is the total power output of the sun? 1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

2. If the radiant energy from the sun comes in as a plane EM wave of intensity {image} calculate the peak values of E and B. 1. 2.
{image} 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

3. If the maximum E-component of an electromagnetic wave is 600 V/m, what is the maximum B-component?1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

4. Find the force exerted by reflecting sunlight off a reflecting aluminum sheet in space if the area normal to the sunlight is {image} and the solar intensity is {image} 1.
0.54 N
54 N
0.68 N
1.1 N
0.14 N 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

5. What is the average value of the magnitude of the Poynting vector S at 1 meter from a 70-watt lightbulb radiating in all directions? 1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

6. A 100-kW radio station emits EM waves in all directions from an antenna on top of a mountain. What is the intensity of the signal at a distance of 7 km? 1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

7. How much electromagnetic energy is contained in each cubic meter near the Earth's surface if the intensity of sunlight under clear skies is {image} 1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

8. At a distance of 12 km from a radio transmitter, the amplitude of the E-field is 0.16 volts/meter. What is the total power emitted by the radio transmitter? 1.
61 kW
772 kW
45 kW
20 kW
38 kW 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

9. What is the maximum radiation pressure exerted by sunlight in space {image} on a flat black surface?1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

10. What is the maximum radiation pressure exerted by sunlight in space {image} on a highly polished silver surface? 1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

11. Find the frequency of X-rays of wavelength {image}1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

12. Green light has a wavelength of {image} What is the frequency of this EM-wave in air?1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

13. An FM radio station broadcasts at 88. 8 MHz
An FM radio station broadcasts at 88.8 MHz. What is the wavelength of the radio waves? 1.
6.76 m
3.38 m
67.6 m
0.45 m
0.296 m 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

14. The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by {image} in SI units. Find the average power per square meter carried by the EM wave. 1.
{image}
62 W
83 W
117 W
234 W 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

15. The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by {image} in SI units. What is the speed of the EM wave? 1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

16. The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by {image} in SI units. What is the wavelength of the EM wave? 1.
39 m
4.3 m
3.3 m
50 m
90 m 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

17. The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by {image} in SI units. What is the frequency of the wave? 1.
1.67 MHz
72 MHz
750 kHz
940 mHz
140 MHz 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

18. What should be the height of a dipole antenna (of dimensions {image} wavelength) if it is to transmit 1,080 kHz radio waves? 1.
93 cm
11.7 m
69.4 m
278 m
88.4 cm 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

19. The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by {image} in SI units. What is the maximum E-field? 1.
390 V/m
76 V/m
4.33 V/m
1,060 V/m
490 V/m 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

20. A solar cell has a light-gathering area of {image} and produces 0
A solar cell has a light-gathering area of {image} and produces 0.4 A at 0.6 V (DC) when illuminated with {image} sunlight. What is the efficiency of the solar cell? 1.
12% 8%
37%
48% 1% 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

21. High frequency alternating current is passed through a solenoid that contains a solid steel core insulated from the coils of the solenoid. Which statement is correct?
The steel core heats up because an emf parallel to the solenoid axis is induced in the core.
The steel core heats up because circular currents around its axis are induced in the core.
A steel core remains cool no matter what the frequency of the current in the solenoid is.
The steel core heats up because the electric field induced in the copper is parallel to the magnetic field produced by the solenoid.
The steel core remains cool because the induced emf is parallel to the solenoid axis and fluctuates rapidly. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

22. 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? (c is the velocity of the light wave.) 1. 2.
{image} 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

23. The intensity of radiation reaching the earth from the sun is {image} The earth's radius is {image} How big a force does this radiation exert on the earth? (Assume it is all absorbed.) 1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

24. What value is the speed of light given by?1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

25. How is the magnetic field amplitude in an electromagnetic wave in vacuum related to the electric field amplitude? 1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

26. Since {image} what are the units of {image}1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

27. When E and B are the amplitudes of the electric and magnetic fields in an electromagnetic wave in vacuum, what is the total average energy density in the wave? 1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

28. In the atmosphere, the shortest wavelength electromagnetic waves are called _____.1.
infrared waves
ultraviolet waves
X-rays
microwaves
gamma rays 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

29. Two identical silver spheres of mass m and radius r are placed a distance R (sphere 1) and 3R (sphere 2) from the sun respectively. What is the ratio of the pressure of solar radiation on sphere 2 to that on sphere 1?
0.11
1.0
0.17
9.0
3.0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

30. What is the phase difference between the sinusoidal oscillations of the electric and magnetic fields in the figure below? {image}
{image}
impossible to determine 1. 2. 3. 4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

31. An electromagnetic wave propagates in the {image} direction
An electromagnetic wave propagates in the {image} direction. The electric field at a point in space is momentarily oriented in the {image} direction. The magnetic field at that point is momentarily oriented in the _____. 1. 2.
{image} direction 3. 4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

32. Which of the following is constant for a plane electromagnetic wave?1. 2.
Magnitude of the Poynting vector.
Energy density {image}
Wave intensity. 3. 4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

33. very black to absorb as much sunlight as possible
To maximize the radiation pressure on the sails of a spacecraft using solar sailing, the sheets should be _____.
very black to absorb as much sunlight as possible
very shiny, to reflect as much sunlight as possible 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

34. In an apparatus such as that in the figure below, the disks are illuminated uniformly over their areas. Suppose the black disk is replaced by one with half the radius. {image} Which of the following are different after the disk is replaced?
Radiation pressure on the disk.
Radiation force on the disk.
Radiation momentum delivered to the disk in a given time interval. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

35. In the figure below the antenna represents the source of a distant radio station. {image} Rank the following points in terms of the intensity of the radiation, from greatest to least: (a) a distance {image} to the right of the antenna, (b) a distance {image} to the left of the antenna, (c) a distance {image} in front of the antenna (out of the page), (d) a distance {image} above the antenna (toward the top of the page).
(a), (b) = (c), (d)
(a) = (d), (b) = (c)
(d), (a), (b), (c)
(d), (b) = (c), (a)
(b) = (c), (a) = (d) 1. 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

36. If the antenna in the figure below represents the source of a distant radio station, what would be the best orientation for your portable radio antenna located to the right of the figure? {image}
Up-down along the page.
Left-right along the page.
Perpendicular to the page. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

37. In many kitchens, a microwave oven is used to cook food
In many kitchens, a microwave oven is used to cook food. The frequency of the microwaves is on the order of {image} The wavelengths of these microwaves are on the order of _____.
kilometers
meters
centimeters
micrometers 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

38. A radio wave of frequency on the order of {image} is used to carry a sound wave with a frequency on the order of {image} The wavelength of this radio wave is on the order of _____.
kilometers
meters
centimeters
micrometers 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

39. Accelerating charges radiate electromagnetic waves
Accelerating charges radiate electromagnetic waves. Calculate the wavelength of radiation produced by a proton moving in a circle of radius {image} perpendicular to a magnetic field of magnitude {image} . 1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

40. A ''laser cannon'' of a spacecraft has a beam of cross-sectional area {image} . The maximum electric field in the beam is {image} . The beam is aimed at an asteroid that is initially moving in the direction of the spacecraft. What is the acceleration of the asteroid relative to the spacecraft if the laser beam strikes the asteroid perpendicular to its surface, and the surface is nonreflecting? The mass of the asteroid is {image} . Ignore the acceleration of the spacecraft. 1.
{image} 2. 3. 4. 5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50