Question 1

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 pressure of solar radiation on sphere 2 to that on sphere 1 is

Accepted Answer

A)  0.25.
B)  0.50.
C)  1.0.
D)  2.0.
E)  4.0.F) C) and E)
G) A) and E)

Question 2

The Earth is 1.49* 1011 meters from the sun.If the solar radiation at the top of the Earth's atmosphere is 1 340 W/m2,what is the total power output of the sun?

Accepted Answer

A)  7.10 * 1027 W
B)  2.20 * 1030 W
C)  6.62 * 1026 W
D)  3.74 * 1026 W
E)  2.98 * 1025 WF) None of the above
G) C) and D)

Question 3

The correct form of Ampere's law for circuits with gaps in them is

Accepted Answer

A)    ∮B⋅ds=0\oint \mathrm { B } \cdot d \mathbf { s } = 0∮B⋅ds=0  .
B)    ∮B⋅ds=Ienciosed \oint \mathbf { B } \cdot d \mathbf { s } = I _ { 	ext {enciosed } }∮B⋅ds=Ienciosed ​  .
C)    ∮B⋅ds=μ0Ienclosed \oint \mathbf { B } \cdot d \mathbf { s } = \mu _ { 0 } I _ { 	ext {enclosed } }∮B⋅ds=μ0​Ienclosed ​  .
D)    ∮B⋅ds=μ0Ienclosed +μ0ε0dΦEdt\oint \mathbf { B } \cdot d \mathbf { s } = \mu _ { 0 } I _ { 	ext {enclosed } } + \mu _ { 0 } \varepsilon _ { 0 } \frac { d \Phi _ { E } } { d t }∮B⋅ds=μ0​Ienclosed ​+μ0​ε0​dtdΦE​​  .
E)    ∮B⋅ds=μ0Ienclosed +μ0ε0dΦIdt−ε0(μ0) 2dΦBdt\oint \mathbf { B } \cdot d \mathbf { s } = \mu _ { 0 } I _ { 	ext {enclosed } } + \mu _ { 0 } \varepsilon _ { 0 } \frac { d \Phi _ { I } } { d t } - \frac { \varepsilon _ { 0 } } { \left( \mu _ { 0 } ight)  ^ { 2 } } \frac { d \Phi _ { B } } { d t }∮B⋅ds=μ0​Ienclosed ​+μ0​ε0​dtdΦI​​−(μ0​) 2ε0​​dtdΦB​​  . F) All of the above
G) A) and E)

Question 4

Find the frequency of X-rays of wavelength 1 Å = 10-10 m.

Accepted Answer

A)  3 * 1018 Hz
B)  3 * 1010 MHz
C)  6 * 109 Hz
D)  3 * 108 Hz
E)  3 *1020 HzF) B) and C)
G) All of the above

Question 5

The intensity of radiation reaching the earth from the sun is 1 350 W/m2.The earth's radius is 6.4 * 106 m.How big a force does this radiation exert on the earth? (Assume it is all absorbed. )

Accepted Answer

A)  5.8 * 108 N
B)  1.2 * 109 N
C)  2.3 * 109 N
D)  4.6 *109 N
E)  1.7 *1017 NF) A) and E)
G) B) and C)

Question 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 10 km?

Accepted Answer

A)  8*10 - 5 W/m2
B)  8 *10 - 6 W/m2
C)  3 *10 - 3 W/m2
D)  0.8 W/m2
E)  2.5 *10 1- 5 W/m2F) A) and E)
G) D) and E)

Question 7

Magnetic fields are produced by

Accepted Answer

A)  constant electric currents.
B)  electric currents that vary sinusoidally with time.
C)  time-varying electric fields.
D)  all of the above.
E)  only (a) and (b) above.F) C) and D)
G) None of the above

Question 8

Near the surface of the planet,the Earth's magnetic field is about 0.50 *10 1- 4 T.How much energy is stored in 1.0 m3 of the atmosphere because of this field?

Accepted Answer

9.9 *10 <s...

Question 9

The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by 
 B=1.2×10−6sin⁡[2π(z240−t×1078) ]B = 1.2 	imes 10 ^ { - 6 } \sin \left[ 2 \pi \left( \frac { z } { 240 } - \frac { t 	imes 10 ^ { 7 } } { 8 } ight)  ight]B=1.2×10−6sin[2π(240z​−8t×107​) ] 
 in SI units.What is the wavelength of the EM wave?

Accepted Answer

A)  120 m
B)  240 m
C)  60 m
D)  100 m
E)  360 m F) B) and C)
G) B) and D)

Question 10

The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by 
 B=1.2×10−6sin⁡[2π(z240−t×1078) ]B = 1.2 	imes 10 ^ { - 6 } \sin \left[ 2 \pi \left( \frac { z } { 240 } - \frac { t 	imes 10 ^ { 7 } } { 8 } ight)  ight]B=1.2×10−6sin[2π(240z​−8t×107​) ] 
 in SI units.What is the speed of the EM wave?

Accepted Answer

A)  3* 108 m/s
B)  100 m/s
C)  106 m/s
D)  2 * 107 m/s
E)  2 * 108 m/s F) A) and D)
G) A) and B)

Question 11

The speed of light is given by the value of

Accepted Answer

A)   ε\varepsilonε 0 μ\muμ 0.
B)    ε0μ0\sqrt { \varepsilon _ { 0 } \mu _ { 0 } }ε0​μ0​c-2.7,0,-7.17,-2.7,-13.5,-8c-5.8,-5.3,-9.5,-10,-9.5,-14c0,-2,0.3,-3.3,1,-4c1.3,-2.7,23.83,-20.7,67.5,-54c44.2,-33.3,65.8,-50.3,66.5,-51c1.3,-1.3,3,-2,5,-2c4.7,0,8.7,3.3,12,10s173,378,173,378c0.7,0,35.3,-71,104,-213c68.7,-142,137.5,-285,206.5,-429c69,-144,104.5,-217.7,106.5,-221l0 -0c5.3,-9.3,12,-14,20,-14H400000v40H845.2724s-225.272,467,-225.272,467s-235,486,-235,486c-2.7,4.7,-9,7,-19,7c-6,0,-10,-1,-12,-3s-194,-422,-194,-422s-65,47,-65,47zM834 80h400000v40h-400000z'/>​  .
C)    1ε0μ0\frac { 1 } { \sqrt { \varepsilon _ { 0 } \mu _ { 0 } } }ε0​μ0​c-2.7,0,-7.17,-2.7,-13.5,-8c-5.8,-5.3,-9.5,-10,-9.5,-14c0,-2,0.3,-3.3,1,-4c1.3,-2.7,23.83,-20.7,67.5,-54c44.2,-33.3,65.8,-50.3,66.5,-51c1.3,-1.3,3,-2,5,-2c4.7,0,8.7,3.3,12,10s173,378,173,378c0.7,0,35.3,-71,104,-213c68.7,-142,137.5,-285,206.5,-429c69,-144,104.5,-217.7,106.5,-221l0 -0c5.3,-9.3,12,-14,20,-14H400000v40H845.2724s-225.272,467,-225.272,467s-235,486,-235,486c-2.7,4.7,-9,7,-19,7c-6,0,-10,-1,-12,-3s-194,-422,-194,-422s-65,47,-65,47zM834 80h400000v40h-400000z'/>​1​  .
D)    1ε0μ0\frac { 1 } { \varepsilon _ { 0 } \mu _ { 0 } }ε0​μ0​1​  .
E)    ε0μ0\sqrt { \frac { \varepsilon _ { 0 } } { \mu _ { 0 } } }μ0​ε0​​l0 -0c4,-6.7,10,-10,18,-10 H400000v40H1013.1s-83.4,268,-264.1,840c-180.7,572,-277,876.3,-289,913c-4.7,4.7,-12.7,7,-24,7s-12,0,-12,0c-1.3,-3.3,-3.7,-11.7,-7,-25c-35.3,-125.3,-106.7,-373.3,-214,-744c-10,12,-21,25,-33,39s-32,39,-32,39c-6,-5.3,-15,-14,-27,-26s25,-30,25,-30c26.7,-32.7,52,-63,76,-91s52,-60,52,-60s208,722,208,722c56,-175.3,126.3,-397.3,211,-666c84.7,-268.7,153.8,-488.2,207.5,-658.5c53.7,-170.3,84.5,-266.8,92.5,-289.5zM1001 80h400000v40h-400000z'/>​  . F) A) and B)
G) A) and C)

Question 12

The magnetic field amplitude in an electromagnetic wave in vacuum is related to the electric field amplitude by B =

Accepted Answer

A)    Ec\frac { E } { c }cE​  
B)    Ec\frac { E } { \sqrt { c } }cc-2.7,0,-7.17,-2.7,-13.5,-8c-5.8,-5.3,-9.5,-10,-9.5,-14c0,-2,0.3,-3.3,1,-4c1.3,-2.7,23.83,-20.7,67.5,-54c44.2,-33.3,65.8,-50.3,66.5,-51c1.3,-1.3,3,-2,5,-2c4.7,0,8.7,3.3,12,10s173,378,173,378c0.7,0,35.3,-71,104,-213c68.7,-142,137.5,-285,206.5,-429c69,-144,104.5,-217.7,106.5,-221l0 -0c5.3,-9.3,12,-14,20,-14H400000v40H845.2724s-225.272,467,-225.272,467s-235,486,-235,486c-2.7,4.7,-9,7,-19,7c-6,0,-10,-1,-12,-3s-194,-422,-194,-422s-65,47,-65,47zM834 80h400000v40h-400000z'/>​E​  
C)  E
D)    EcE \sqrt { c }Ecc-2.7,0,-7.17,-2.7,-13.5,-8c-5.8,-5.3,-9.5,-10,-9.5,-14c0,-2,0.3,-3.3,1,-4c1.3,-2.7,23.83,-20.7,67.5,-54c44.2,-33.3,65.8,-50.3,66.5,-51c1.3,-1.3,3,-2,5,-2c4.7,0,8.7,3.3,12,10s173,378,173,378c0.7,0,35.3,-71,104,-213c68.7,-142,137.5,-285,206.5,-429c69,-144,104.5,-217.7,106.5,-221l0 -0c5.3,-9.3,12,-14,20,-14H400000v40H845.2724s-225.272,467,-225.272,467s-235,486,-235,486c-2.7,4.7,-9,7,-19,7c-6,0,-10,-1,-12,-3s-194,-422,-194,-422s-65,47,-65,47zM834 80h400000v40h-400000z'/>​  
E)  cE F) B) and D)
G) C) and D)

Question 13

You can raise the temperature of an object with

Accepted Answer

A)  microwaves.
B)  infrared waves.
C)  ultraviolet rays.
D)  all of the above.
E)  only (a) and (b) above.F) All of the above
G) A) and E)

Question 14

A plane parallel plate capacitor has plates of 10 cm2 area that are 1.0 mm apart.At an instant when charge is being accumulated on the plates at a rate of 12 nC/s,the displacement current between the plates is

Accepted Answer

A)  1.06* 10 - 16 A.
B)  1.2 *10 - 8 A.
C)  8.85 * 10 - 9 A.
D)  1.00 A.
E)  1.36 A.F) A) and E)
G) A) and D)

Question 15

When E and B are the amplitudes of the electric and magnetic fields in an electromagnetic wave in vacuum,the total average energy density in the wave is

Accepted Answer

A)    14ε0E2\frac { 1 } { 4 } \varepsilon _ { 0 } E ^ { 2 }41​ε0​E2  .
B)    12ε0E2\frac { 1 } { 2 } \varepsilon _ { 0 } E ^ { 2 }21​ε0​E2  .
C)   ε\varepsilonε 0E2.
D)    B2μ0\frac { B ^ { 2 } } { \mu _ { 0 } }μ0​B2​  .
E)    EBμ0\frac { E B } { \mu _ { 0 } }μ0​EB​  . F) A) and D)
G) All of the above

Question 16

If the maximum E-component of an electromagnetic wave is 600 V/m,what is the maximum B-component?

Accepted Answer

A)  1.4 T
B)  1.8 *10 - 5 T
C)  2.0 / 10 * 6 T
D)  1.0 *10 - 3 T
E)  1.6 *10 - 10 TF) B) and E)
G) All of the above

Question 17

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

Accepted Answer

A)  1.4 *10 - 2 Pa
B)  0.12 Pa
C)  9.0 *10 - 6 Pa
D)  4.5 *10 - 5 Pa
E)  2.3 * 10 - 6 PaF) B) and D)
G) D) and E)

Question 18

Green light has a wavelength of 5.4 *10-7 m.What is the frequency of this EM-wave in air?

Accepted Answer

A)  5.55 * 1014 Hz
B)  6.00 *1011 Hz
C)  9.00* 108 Hz
D)  3.00 * 1010 MHz
E)  1.80* 1015 HzF) B) and E)
G) A) and D)

Question 19

An FM radio station broadcasts at 98.6 MHz.What is the wavelength of the radiowaves?

Accepted Answer

A)  60.8 m
B)  6.08 m
C)  3.04 m
D)  0.314 m
E)  0.33 cmF) B) and E)
G) B) and C)

Question 20

Since  ε\varepsilonε 0 = 8.85 *10 - 12 C2 / N . m2,the units of  ε\varepsilonε 0E2 can be reduced to

Accepted Answer

A)    Js⋅m3\frac { \mathrm { J } } { \mathrm { s } \cdot \mathrm { m } ^ { 3 } }s⋅m3J​  
B)    Ns⋅m3\frac { \mathrm { N } } { \mathrm { s } \cdot \mathrm { m } ^ { 3 } }s⋅m3N​  .
C)    Jm3\frac { \mathrm { J } } { \mathrm { m } ^ { 3 } }m3J​  
D)    Nm3\frac { \mathrm { N } } { \mathrm { m } ^ { 3 } }m3N​  
E)    wm3\frac { w } { m ^ { 3 } }m3w​   F) B) and C)
G) A) and C)

Exam 24: Electromagnetic Waves

Since ε\varepsilonε 0 = 8.85 *10 - 12 C2 / N . m2,the units of ε\varepsilonε 0E2 can be reduced to

Correct AnswerverifiedShow Answer

You can raise the temperature of an object with

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The speed of light is given by the value of

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

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 10 km?

Correct AnswerverifiedShow Answer

Green light has a wavelength of 5.4 *10-7 m.What is the frequency of this EM-wave in air?

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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 pressure of solar radiation on sphere 2 to that on sphere 1 is

Correct AnswerverifiedShow Answer

The intensity of radiation reaching the earth from the sun is 1 350 W/m2.The earth's radius is 6.4 * 106 m.How big a force does this radiation exert on the earth? (Assume it is all absorbed. )

Correct AnswerverifiedShow Answer

Magnetic fields are produced by

Correct AnswerverifiedShow Answer

A plane parallel plate capacitor has plates of 10 cm2 area that are 1.0 mm apart.At an instant when charge is being accumulated on the plates at a rate of 12 nC/s,the displacement current between the plates is

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

An FM radio station broadcasts at 98.6 MHz.What is the wavelength of the radiowaves?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Near the surface of the planet,the Earth's magnetic field is about 0.50 *10 1- 4 T.How much energy is stored in 1.0 m3 of the atmosphere because of this field?

Correct Answerverified9.9 *10 View AnswerShow Answer

The correct form of Ampere's law for circuits with gaps in them is

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The magnetic field amplitude in an electromagnetic wave in vacuum is related to the electric field amplitude by B =

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If the maximum E-component of an electromagnetic wave is 600 V/m,what is the maximum B-component?

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Find the frequency of X-rays of wavelength 1 Å = 10-10 m.

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The Earth is 1.49* 1011 meters from the sun.If the solar radiation at the top of the Earth's atmosphere is 1 340 W/m2,what is the total power output of the sun?

Correct AnswerverifiedShow Answer

When E and B are the amplitudes of the electric and magnetic fields in an electromagnetic wave in vacuum,the total average energy density in the wave is

Correct AnswerverifiedShow Answer

Since $\varepsilon$ ₀ = 8.85 *10 ^- ¹² C² / N . m²,the units of $\varepsilon$ ₀E² can be reduced to

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Green light has a wavelength of 5.4 *10^-⁷ m.What is the frequency of this EM-wave in air?

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The intensity of radiation reaching the earth from the sun is 1 350 W/m².The earth's radius is 6.4 * 10⁶ m.How big a force does this radiation exert on the earth? (Assume it is all absorbed. )

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A plane parallel plate capacitor has plates of 10 cm² area that are 1.0 mm apart.At an instant when charge is being accumulated on the plates at a rate of 12 nC/s,the displacement current between the plates is

Correct Answer
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Correct Answer
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What is the maximum radiation pressure exerted by sunlight in space (S = 1 350 W/m²) on a highly polished silver surface?

Correct Answer
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Near the surface of the planet,the Earth's magnetic field is about 0.50 *10 1^- ⁴ T.How much energy is stored in 1.0 m³ of the atmosphere because of this field?

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9.9 *10
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Find the frequency of X-rays of wavelength 1 Å = 10^-¹⁰ m.

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The Earth is 1.49* 10¹¹ meters from the sun.If the solar radiation at the top of the Earth's atmosphere is 1 340 W/m²,what is the total power output of the sun?

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