Question 1

If you are facing north with the Sun directly overhead,the light coming to your eyes from the sky just above the horizon is

Accepted Answer

A)  partially polarized east-west. 
B)  partially polarized north-south. 
C)  randomly polarized. 
D)  partially polarized up-down.

Question 2

What is a light-year in SI units?

Accepted Answer

A)  3.0 $\times$ 1015 m 
B)  9.5 $\times$ 1015 m 
C)  3.0 $\times$ 1011 m 
D)  1.1 $\times$ 1011 m 
E)  4.5 $\times$ 1037 m

Question 3

Plane polarized light of intensity I0 is passed through a polarizer oriented at 45$^{\circ}$to the original plane of polarization.What is the intensity transmitted?

Accepted Answer

A)  0.70 I0 
B)  0.50 I0 
C)  0.35 I0 
D)  0.25 I0 
E)  0.00

Question 4

What is the wave number for a wavelength of 600 nm?

Accepted Answer

A)  600 nm 
B)  1.67 $\times$ 106 m-1 
C)  1.05 $\times$ 107 m-1 
D)  9.55 $\times$ 10-8 m 
E)  9.55 $\times$ 10-8 m-1

Question 5

How long does it take for a radio signal to travel to a spacecraft 1.5 $\times$ 1011 m away?

Accepted Answer

A)  5.0 s 
B)  50 s 
C)  5.0 $\times$ 102 s 
D)  5.0 $\times$ 103 s 
E)  1.0 $\times$ 103 s

Question 6

$\varepsilon$o $\mu$o = ?

Accepted Answer

A)  c 
B)  c2 
C)  c-1 
D)  c-2 
E)  c½

Question 7

At the Earth's orbital distance,the intensity of the solar radiation is approximately 1400 W/m2.What is the value for the rms Electric field strength in solar radiation?

Accepted Answer

A)  726 V/m 
B)  363 kV/m 
C)  527 kV/m 
D)  513 kV/m

Question 8

A magnetic dipole antenna is set up due west of a radio installation that utilizes an electric dipole antenna as a transmitter.What should the orientation of the antenna be used?

Accepted Answer

A)  east-west 
B)  horizontal 
C)  north-south 
D)  Unable to answer given the information. 
E)  vertical

Question 9

The wavelengths associated with thermal radiation at everyday temperatures are in the ________ spectral region.

Accepted Answer

A)  infrared 
B)  ultraviolet 
C)  shorter visual 
D)  longer visual 
E)  x-ray

Question 10

It is possible to detect Doppler shifts due to light on each side of a rapidly spinning star.Suppose it is seen that a nearby star,relatively stationary to us,is blueshifted in light on one side of the star and redshifted in the light from the other side.Suppose a star of radius 2.5 $\times$ 108 km has light shifted from 525 nm to 527 nm on one side and to 523 nm on the other.What is the rotational period of the star?

Accepted Answer

A)  34 h 
B)  32 h 
C)  24 h 
D)  16 h

Question 11

At a distance of 10 m from a light bulb the rms value of the electric field is 16 V/m.What is the rms value of the electric field at a distance of 20 m from the light bulb?

Accepted Answer

A)  32 V/m 
B)  16 V/m 
C)  8.0 V/m 
D)  4.0 V/m 
E)  2.0 V/m

Question 12

What index of refraction halves the wavelength that light has in a vacuum?

Accepted Answer

A)  1.33 
B)  1.50 
C)  1.41 
D)  2.00 
E)  5.00

Question 13

The speed of an electromagnetic wave in vacuum depends on

Accepted Answer

A)  the amplitude of the electric and magnetic fields. 
B)  the frequency of the wavelength. 
C)  none of these choices are correct 
D)  the angle between the electric and magnetic fields.

Question 14

If unpolarized light with Erms = 20 V/m is passed through a polarizer,what is the transmitted Erms?

Accepted Answer

A)  20 V/m 
B)  14 V/m 
C)  10 V/m 
D)  7.1 V/m 
E)  5.0 V/m

Question 15

Randomly polarized light of intensity I0 is passed through two polarizers whose transmission axes differ by 45$^{\circ}$.What is the intensity of the light that has passed through both polarizers?

Accepted Answer

A)  0.70 I0 
B)  0.50 I0 
C)  0.35 I0 
D)  0.25 I0 
E)  0.00

Question 16

At the Earth's orbital distance,the intensity of the solar radiation is approximately 1400 W/m2.What is the value for the intensity at Mercury's orbital distance,which is 38.7% the distance to the sun that the Earth is.

Accepted Answer

A)  2280 W/m2 
B)  3800 W/m2 
C)  9300 W/m2 
D)  540 W/m2

Question 17

At the Earth's surface,approximately 1000 W/m2 is present due to solar radiation.At a latitude of 44.5 degrees North,the angle of the sun's rays,when the sun is highest in the sky on the winter solstice,are incident at an angle of 68 degrees from the vertical.What power is incident upon a 1.0 m $\times$ 1.5 m window in a vertical,south-facing wall at this time?

Accepted Answer

A)  1390 W 
B)  930 W 
C)  560 W 
D)  370 W

Question 18

Plane polarized light of intensity I0 is passed through two polarizers,the first one at 45$^{\circ}$to the original plane of polarization and the second rotated an additional 45$^{\circ}$more so that it is perpendicular to the original plane of polarization.What intensity is transmitted?

Accepted Answer

A)  0.50 I0 
B)  0.35 I0 
C)  0.25 I0 
D)  0.13 I0 
E)  0

Question 19

Light from an astronomical source is found to be shifted to a one percent lower frequency than had the source been at rest.What radial velocity could cause such a shift?

Accepted Answer

A)  3.0 $\times$ 107 m/s moving away from the observer 
B)  3.0 $\times$ 106 m/s moving away from the observer 
C)  3.0 $\times$ 106 m/s moving toward the observer 
D)  1.5 $\times$ 106 m/s moving toward the observer 
E)  1.5 $\times$ 106 m/s moving away from the observer

Question 20

1 THz = ?

Accepted Answer

A)  103 Hz 
B)  106 Hz 
C)  109 Hz 
D)  1012 Hz 
E)  1015 Hz

Exam 22: Electromagnetic Waves

If you are facing north with the Sun directly overhead,the light coming to your eyes from the sky just above the horizon is

What is a light-year in SI units?

Plane polarized light of intensity I₀ is passed through a polarizer oriented at 45 $^{\circ}$ to the original plane of polarization.What is the intensity transmitted?

What is the wave number for a wavelength of 600 nm?

How long does it take for a radio signal to travel to a spacecraft 1.5 $\times$ 10¹¹ m away?

$\varepsilon$ _o $\mu$ _o = ?

At the Earth's orbital distance,the intensity of the solar radiation is approximately 1400 W/m².What is the value for the rms Electric field strength in solar radiation?

A magnetic dipole antenna is set up due west of a radio installation that utilizes an electric dipole antenna as a transmitter.What should the orientation of the antenna be used?

The wavelengths associated with thermal radiation at everyday temperatures are in the ________ spectral region.

At a distance of 10 m from a light bulb the rms value of the electric field is 16 V/m.What is the rms value of the electric field at a distance of 20 m from the light bulb?

What index of refraction halves the wavelength that light has in a vacuum?

The speed of an electromagnetic wave in vacuum depends on

If unpolarized light with E_rms = 20 V/m is passed through a polarizer,what is the transmitted E_rms?

Randomly polarized light of intensity I₀ is passed through two polarizers whose transmission axes differ by 45 $^{\circ}$ .What is the intensity of the light that has passed through both polarizers?

At the Earth's orbital distance,the intensity of the solar radiation is approximately 1400 W/m².What is the value for the intensity at Mercury's orbital distance,which is 38.7% the distance to the sun that the Earth is.

Plane polarized light of intensity I₀ is passed through two polarizers,the first one at 45 $^{\circ}$ to the original plane of polarization and the second rotated an additional 45 $^{\circ}$ more so that it is perpendicular to the original plane of polarization.What intensity is transmitted?

Light from an astronomical source is found to be shifted to a one percent lower frequency than had the source been at rest.What radial velocity could cause such a shift?

1 THz = ?

Exam 22: Electromagnetic Waves

If you are facing north with the Sun directly overhead,the light coming to your eyes from the sky just above the horizon is

What is a light-year in SI units?

Plane polarized light of intensity I0 is passed through a polarizer oriented at 45 ∘^{\circ}∘ to the original plane of polarization.What is the intensity transmitted?

What is the wave number for a wavelength of 600 nm?

How long does it take for a radio signal to travel to a spacecraft 1.5 ×\times× 1011 m away?

ε\varepsilonε o μ\muμ o = ?

At the Earth's orbital distance,the intensity of the solar radiation is approximately 1400 W/m2.What is the value for the rms Electric field strength in solar radiation?

A magnetic dipole antenna is set up due west of a radio installation that utilizes an electric dipole antenna as a transmitter.What should the orientation of the antenna be used?

The wavelengths associated with thermal radiation at everyday temperatures are in the ________ spectral region.

At a distance of 10 m from a light bulb the rms value of the electric field is 16 V/m.What is the rms value of the electric field at a distance of 20 m from the light bulb?

What index of refraction halves the wavelength that light has in a vacuum?

The speed of an electromagnetic wave in vacuum depends on

If unpolarized light with Erms = 20 V/m is passed through a polarizer,what is the transmitted Erms?

Randomly polarized light of intensity I0 is passed through two polarizers whose transmission axes differ by 45 ∘^{\circ}∘ .What is the intensity of the light that has passed through both polarizers?

At the Earth's orbital distance,the intensity of the solar radiation is approximately 1400 W/m2.What is the value for the intensity at Mercury's orbital distance,which is 38.7% the distance to the sun that the Earth is.

Light from an astronomical source is found to be shifted to a one percent lower frequency than had the source been at rest.What radial velocity could cause such a shift?

1 THz = ?

Plane polarized light of intensity I₀ is passed through a polarizer oriented at 45 $^{\circ}$ to the original plane of polarization.What is the intensity transmitted?

How long does it take for a radio signal to travel to a spacecraft 1.5 $\times$ 10¹¹ m away?

$\varepsilon$ _o $\mu$ _o = ?

At the Earth's orbital distance,the intensity of the solar radiation is approximately 1400 W/m².What is the value for the rms Electric field strength in solar radiation?

If unpolarized light with E_rms = 20 V/m is passed through a polarizer,what is the transmitted E_rms?

Randomly polarized light of intensity I₀ is passed through two polarizers whose transmission axes differ by 45 $^{\circ}$ .What is the intensity of the light that has passed through both polarizers?

At the Earth's orbital distance,the intensity of the solar radiation is approximately 1400 W/m².What is the value for the intensity at Mercury's orbital distance,which is 38.7% the distance to the sun that the Earth is.