kuruturi (rk8237) – HW-007 – chen – (81485) 1

This print-out should have 15 questions.Multiple-choice questions may continue onthe next column or page – find all choicesbefore answering.

001 (part 1 of 6) 10.0 pointsWhich of Maxwell’s equations can be used,along with a symmetry argument, to calculatethe electric field of a point charge?

1.

∮~B · d~s = 0

2.

∮~E · d~A = −

∂ ΦB

∂t

3.

∮~E · d~A =

Q

ǫ0

4.

∮~E · d~s = −

∂ ΦB

∂t

5.

∮~B · d~A = µ0 I

6.

∮~E · d~s =

Q

ǫ0

7.

∮~B · d~A = 0

8.

∮~B · d~A = µ0 ǫ0

∂ ΦE

∂t

9.

∮~B · d~s = µ0 I + µ0 ǫ0

∂ ΦE

∂t

10.

∮~B · d~A =

Q

ǫ0

002 (part 2 of 6) 10.0 pointsWhich of Maxwell’s equations can be used,along with a symmetry argument, to calcu-late the magnetic field produced by a uniformtime-varying electric field?

1.

∮~B · d~A = 0

2.

∮~B · d~s = 0

3.

∮~B · d~A = µ0 I

4.

∮~B · d~A =

Q

ǫ0

5.

∮~E · d~s = −

∂ ΦB

∂t

6.

∮~E · d~s =

Q

ǫ0

7.

∮~B · d~A = µ0 ǫ0

∂ ΦE

∂t

8.

∮~E · d~A =

Q

ǫ0

9.

∮~B · d~s = µ0 I + µ0 ǫ0

∂ ΦE

∂t

10.

∮~E · d~A = −

∂ ΦB

∂t

003 (part 3 of 6) 10.0 pointsWhich of Maxwell’s equations can be used,along with a symmetry argument, to calculatethat magnetic field lines form closed loops?

1.

∮~B · d~A =

Q

ǫ0

2.

∮~B · d~A = µ0 I

3.

∮~E · d~A = −

∂ ΦB

∂t

4.

∮~B · d~s = µ0 I + µ0 ǫ0

∂ ΦE

∂t

5.

∮~B · d~A = µ0 ǫ0

∂ ΦE

∂t

6.

∮~E · d~A =

Q

ǫ0

7.

∮~B · d~A = 0

8.

∮~B · d~s = 0

9.

∮~E · d~s = −

∂ ΦB

∂t

10.

∮~E · d~s =

Q

ǫ0

004 (part 4 of 6) 10.0 pointsWhich of Maxwell’s equations can be used,along with a symmetry argument, to calculatethe magnetic field of a long straight current-carrying wire?

1.

∮~E · d~A =

Q

ǫ0

kuruturi (rk8237) – HW-007 – chen – (81485) 2

2.

∮~B · d~s = 0

3.

∮~B · d~A = µ0 I

4.

∮~E · d~s =

Q

ǫ0

5.

∮~B · d~A =

Q

ǫ0

6.

∮~B · d~A = µ0 ǫ0

∂ ΦE

∂t

7.

∮~E · d~A = −

∂ ΦB

∂t

8.

∮~E · d~s = −

∂ ΦB

∂t

9.

∮~B · d~A = 0

10.

∮~B · d~s = µ0 I + µ0 ǫ0

∂ ΦE

∂t

005 (part 5 of 6) 10.0 pointsWhich of Maxwell’s equations can be used,along with a symmetry argument, to calculatethe electric field produced by a uniform time-varying magnetic field?

1.

∮~E · d~s = −

∂ ΦB

∂t

2.

∮~E · d~s =

Q

ǫ0

3.

∮~B · d~A =

Q

ǫ0

4.

∮~E · d~A = −

∂ ΦB

∂t

5.

∮~B · d~A = µ0 I

6.

∮~B · d~A = µ0 ǫ0

∂ ΦE

∂t

7.

∮~E · d~A =

Q

ǫ0

8.

∮~B · d~s = µ0 I + µ0 ǫ0

∂ ΦE

∂t

9.

∮~B · d~s = 0

10.

∮~B · d~A = 0

006 (part 6 of 6) 10.0 pointsCan Maxwell’s equations be used, along withstatic measurements for µ0 and ǫ0, to deter-mine the speed of light?

1. No, the speed of light can only be deter-mined by directly measuring its speed.

2. Yes, the speed of light can be determinedusing only static measurements for µ0 andǫ0.

3. No, the speed of light depends on itsfrequency times Plank’s constant, which arenot contained in Maxwell’s equations.

007 10.0 points

Consider an electromagnetic wave patternas shown in the figure below.

z

y

vdirection

If the wave is traveling left to right (as

shown) and the ~E vector is along the negativey direction,

1. then the ~B vector is along the positive zdirection.

2. Cannot be determined since the waveshown in the figure is a standing wave and isstationary.

3. then the ~B vector is along the negative zdirection.

008 (part 1 of 2) 10.0 pointsDetermine whether the statements below aretrue or false.

In a traveling plane wave, the maxima of ~Eand of ~B alternate in space.

kuruturi (rk8237) – HW-007 – chen – (81485) 3

1. true

2. false

009 (part 2 of 2) 10.0 points

In a traveling plane wave, the amplitude of ~Ecan be adjusted independently of the ampli-tude of ~B.

1. false

2. true

010 10.0 points

Consider an electromagnetic wave patternas shown in the figure below.

E

B

The wave is

1. traveling left to right.

2. a standing wave and is stationary.

3. traveling right to left.

011 (part 1 of 2) 10.0 pointsIf the frequency of an electromagnetic wave is1 × 106 Hz what is the wavelength?

Answer in units of nm.

012 (part 2 of 2) 10.0 pointsWhat type of electromagnetic wave is this?

1. microwave

2. ultraviolet

3. visible light

4. gamma rays

5. infrared

6. X-rays

7. radio wave

013 10.0 pointsThe intensity of sunlight under the clear skyis 904 W/m2.

How much electromagnetic energy is con-tained per cubic meter near the Earth’s sur-face? The speed of light is 2.99792 × 108 m/s.

Answer in units of J/m3.

014 10.0 pointsAn electromagnetic wave is traveling throughfree space. At a particular instant of time theelectric field at a point is 3700 V/m.

The speed of light is 2.998 × 108 m/s.Find the magnetic field at the same time

and at the same place as above.Answer in units of T.

015 10.0 pointsHow does the average speed of light in glasscompare with its speed in a vacuum?

1. It cannot be judged because we don’tknow what kind of glass it is.

2. The speed of light in glass is higher.

3. There is no difference between the speedof light in glass and in a vacuum.

4. The speed of light in glass is lower.

5. For colorless glass, the light speed ishigher than in a vacuum; for colored glass,the light speed is lower than in vacuum.