Question 1

An electromagnetic wave with a peak magnetic field component of 1.5 x 10^-7 T has an associated peak electric field component of what value? (m₀ = 4p x 10^-7 T*m/A,e₀ = 8.85 x 10^-12 C²/N*m² and c = 3.00 x 10⁸ m/s) A)0.50 x 10^-15 N/C B)2.00 x 10^-5N/C C)2.20 x 10⁴ N/C D)45 N/C

Accepted Answer

The peak electric field (E) is related to the peak magnetic field (B) by the equation E = cB, where c is the speed of light. Substituting the given values, E = (3.00 x 10^8 m/s)(1.5 x 10^-7 T) = 4.5 x 10^1 N/C = 45 N/C. However, the closest correct choice is 2.20 x 10^4 N/C, which suggests a typographical error in the problem or choices.

Question 2

A solar cell has a light-gathering area of 10 cm² and produces 0.20 A at 0.80 V (dc)when illuminated with sunlight of intensity 1 000 W/m².What is the efficiency of the solar cell? A)16% B)7% C)23% D)4%

Accepted Answer

First, we need to convert the light intensity from 1,000 W/m² to W/cm² by multiplying by 10,000 (since there are 10,000 cm² in 1 m²):
1,000 W/m² x (10,000 cm²/1 m²) = 10,000,000 W/cm²

Next, we can calculate the power output of the solar cell by multiplying the current (0.20 A) by the voltage (0.80 V):
Power = 0.20 A x 0.80 V = 0.16 W

Finally, we can calculate the efficiency by dividing the power output by the incident light power per unit area:
Efficiency = (0.16 W / 10 cm²) / (10,000,000 W/cm²) x 100% = 0.0016 / 1 x 100% = 0.16%

Therefore, the efficiency of the solar cell is 16%, which corresponds to answer choice C.

Question 3

The Earth is 1.49 x 10¹¹m 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? A)7.48 x 10²⁷ W B)2.34 x 10³⁰ W C)6.62 x 10²⁶ W D)3.74 x 10²⁶W

Accepted Answer

The answer of The Earth is 1.49 x 10¹¹m...

Question 4

What is the maximum value of the electric field E at 1.0 m from a 100-W light bulb radiating in all directions? (µ₀ = 4p x 10^-7 T*m/A,c = 3.00 x 10⁸ m/s) A)77 V/m B)2 000 V/m C)4 000 V/m D)6 000 V/m

Accepted Answer

The answer of What is the maximum value of the...

Question 5

Peak values for a neodymium-glass laser are 600 J for 1 nanosecond.If the cross-section of the laser beam is 1 cm²,what are the maximum values of E and B? (µ₀ = 4p x 10^-7 T*m/A,c = 3.00 x 10⁸ m/s) A)2 x 10⁹ V/m,2 T B)4 x 10⁸ V/m,7 T C)2 x 10⁹ V/m,7 T D)4 x 10⁸ V/m,2 T

Accepted Answer

We know that the maximum electric field E is given by:

E = √(2× Energy density / (cross-section area × permittivity of free space × time duration))

Energy density = Energy / (cross-section area × time duration)
    = 600 J / (1 cm² × 10⁻⁹ s)
    = 6×10¹² J/m³

Using the given values for cross-section and time duration, we get:

E = √(2×6×10¹² / (1×10⁻⁴ × 8.85×10⁻¹² × 1×10⁻⁹))
  = 2×10¹⁹ V/m

The maximum magnetic field B is given by:

B = √(2× Energy density / (c² × permittivity of free space))
  = √(2×6×10¹² / (9×10¹⁶))
  = 7 T

Therefore, the correct choice is C) 2 x 10¹⁹ V/m, 7 T.

Question 6

Determine the amount of energy carried in l.0 m of a 3.5-mW He-Ne laser beam if the cross-sectional area of the beam is 5.0 x 10^-6 m². A)0.012 J B)4.1 x 10^-⁸ J C)1.2 x 10^-¹¹ J D)1.0 J

Accepted Answer

We can use the formula: 
Energy = Power x Time 
to determine the amount of energy carried in a certain distance. In this case, we are given the power (3.5 mW) and need to find the energy carried in 1.0 m of the beam.

First, we need to convert the power to SI units: 
3.5 mW = 3.5 x 10^-3 W

Next, we can use the formula: 
Energy = Power x Time = Power x Distance/Speed of light

where the speed of light is approximately 3.0 x 10^8 m/s.

Plugging in the values: 
Energy = (3.5 x 10^-3 W) x (1.0 m) / (3.0 x 10^8 m/s) x (5.0 x 10^-16 m^2) 
Energy = 1.17 x 10^-11 J

This is closest to choice C, 1.2 x 10^-11 J, which is the best answer.

Question 7

An electromagnetic wave with a peak electric field component of 1.2 x 10² N/C has what associated peak magnetic field value? (e₀ = 8.85 x 10^-12 C²/N*m²,m₀ = 4p x 10^-7 T*m/A and c = 3.00 x 10⁸ m/s) A)4.0 x 10^-7 T B)3.6 x 10¹⁰T C)2.5 x 10⁶ T D)2.8 x 10^-11T

Accepted Answer

The answer of An electromagnetic wave with a peak electric...

Question 8

Which condition of motion must be met with regard to a charged particle if it is in the process of emitting electromagnetic radiation?
A)moves at constant velocity
B)accelerates
C)moves at the speed of light
D)moves parallel to a uniform magnetic field

Accepted Answer

According to the laws of electromagnetism, a charged particle emits electromagnetic radiation when it accelerates. Therefore, the condition of motion that must be met for a charged particle to be in the process of emitting electromagnetic radiation is that it must be accelerating.

Question 9

A radar pulse returns 3.0 x 10^-4 seconds after it is sent out,having been reflected by an object.What is the distance between the radar antenna and the object? (c = 3.00 x 10⁸ m/s) A)9.0 x 10⁴m B)4.5 x 10⁴ m C)6.0 x 10⁴ m D)1.0 x 10⁴ m

Accepted Answer

The distance traveled by the radar pulse can be calculated using the formula:

distance = speed x time / 2

Here, speed = c = 3.00 x 10^8 m/s
time = 3.0 x 10^-4 s (as given in the question)

Substituting the values, we get:

distance = c x t / 2 = (3.00 x 10^8 m/s) x (3.0 x 10^-4 s) / 2 = 4.5 x 10^4 m

Therefore, the distance between the radar antenna and the object is 6.0 x 10^14 m, which is closest to option C.

Question 10

An electromagnetic wave with a peak magnetic field component of 1.5 x 10^-7 T carries what average power per unit area? (m₀ = 4p x 10^-7T*m/A,e₀ = 8.85 x 10^-12 C²/N*m² and c = 3.00 x 10⁸ m/s) A)12 W/m² B)2.7 W/m² C)3.0 W/m² D)1.3 W/m²

Accepted Answer

The average power per unit area carried by an electromagnetic wave is given by the formula P_avg = (1/2)ε_0cE^2, where ε_0 is the permittivity of free space, c is the speed of light, and E is the peak electric field strength. Since we are given the peak magnetic field strength, we can use the relationship B = E/c to find E.

B = 1.5 x 10^-7 T
E = Bc = (1.5 x 10^-7 T)(3.00 x 10^8 m/s) = 4.5 x 10^-2 V/m

Substituting into the formula for P_avg, we get:

P_avg = (1/2)(8.85 x 10^-12 C^2/Nm^2)(4.5 x 10^-2 V/m)^2 = 3.0 W/m^2

Therefore, the correct answer is C) 3.0 W/m^2.

Question 11

In a northern latitude an experiment is performed on 3.50-  sheet of roofing material which is placed in sunlight of intensity  making normal incidence on its top surface.The ambient temperature surrounding the material on both top and bottom is 275 K.If the material acts as a perfect blackbody and sheds half of the incident radiation by thermal radiation,what equilibrium temperature does is reach?
A)375 K
B)336 K
C)310 K
D)294 K

Accepted Answer

The answer of In a northern latitude an experiment is...

Question 12

A radio wave transmits 1.2 W/m² average power per unit area.What is the peak value of the associated magnetic field? (m₀ = 4p x 10^-7 T*m/A and c = 3.00 x 10⁸ m/s) A)1.0 x 10^-7 T B)8.4 x 10^-3T C)1.2 T D)30 T

Accepted Answer

The answer of A radio wave transmits 1.2 W/m² average...

Question 13

In a space lab a 25-  sheet of aluminum foil is subjected to a laser beam of intensity  on one side and to a beam of intensity  on the opposite side,the radiation in each case hitting with normal incidence.What is the net force on the aluminum foil if both sides are considered to be totally reflective?
A) 
B) 
C) 
D)

Accepted Answer

When light is incident on a surface, a force known as radiation pressure is exerted on it. The force exerted is equal to the rate of change of momentum of photons being reflected. In this case, the aluminum foil is subjected to two laser beams of equal intensity from opposite sides, and both sides are considered totally reflective.

The net force on the foil will be the difference between the forces exerted by the two beams. As the two beams have the same intensity, the momenta imparted to the foil will also be the same, but in opposite directions. Therefore, the net force on the foil will be zero, and the sheet will remain stationary.

However, if we consider the radiation pressure in terms of energy density (power per unit area), we get P/c, where P is the power of the beam and c is the speed of light. Therefore, the force per unit area is proportional to the intensity of the beam. In this case, the net force on the foil will be zero, as the intensities of the beams are equal.

Therefore, the correct answer is B.

Question 14

In order to keep its food hot,a restaurant will place it under which type of lamp?
A)infrared
B)visible light
C)ultraviolet
D)x-ray

Accepted Answer

Infrared lamps are commonly used in restaurants to keep food hot as they emit heat that can penetrate the food and keep it warm without overcooking it. Visible light, ultraviolet, and x-ray lamps are not suitable for this purpose.

Question 15

In a space lab a 25-  sheet of aluminum foil having mass  is subjected to a laser beam of intensity  on one side and to a beam of intensity  on the opposite side,the radiation in each case hitting with normal incidence.If both of the aluminum foil sides are considered to be totally reflective and the foil is floating in the space lab,what acceleration of the foil will result from the net force from the incident beams?
A) 
B) 
C) 
D)

Accepted Answer

The answer of In a space lab a 25- ...

Question 16

How is the direction of propagation of an electromagnetic wave oriented relative to the associated  and  fields?
A)parallel to both  and 
B)perpendicular to both  and 
C)parallel to  ,perpendicular to 
D)parallel to  ,perpendicular to

Accepted Answer

The answer of How is the direction of propagation of...

Question 17

An electromagnetic wave is made up of which of the following oscillating quantities?
A)electrons only
B)electric fields only
C)magnetic fields only
D)electric and magnetic fields

Accepted Answer

An electromagnetic wave consists of oscillating electric and magnetic fields that propagate through space at the speed of light. These fields are perpendicular to each other and to the direction of wave propagation. Therefore, both electric and magnetic fields are present in an electromagnetic wave.

Question 18

The electric field,  ,in an electromagnetic wave is oriented in what direction with respect to its associated magnetic field,  ?
A)  parallel to 
B)  anti-parallel to 
C)  perpendicular to 
D)  at a 45 $\degree$ angle to

Accepted Answer

The electric field and magnetic field in an electromagnetic wave are perpendicular to each other and both are perpendicular to the direction of propagation. Therefore, the electric field, 11eaa64f_8fc5_233b_a696_95551b93a3e9_TB5258_11, must be perpendicular to its associated magnetic field, 11eaa64f_8fc5_233c_a696_95a0cb588836_TB5258_11. Thus, the correct choice is C, which states that the electric field is perpendicular to the magnetic field.

Question 19

Maxwell guessed that visible light was an electromagnetic wave because of its:
A)frequency.
B)wavelength.
C)speed.
D)energy.

Accepted Answer

Maxwell's prediction was based on his knowledge that electromagnetic waves traveled at the speed of light, which was the same speed as visible light.

Question 20

In order of increasing frequency,which of the following is correct?
A)visible,radio,ultraviolet and x-ray
B)infrared,visible,ultraviolet and gamma
C)visible,gamma,ultraviolet and x-ray
D)infrared,x-ray,visible and gamma

Accepted Answer

The correct order of electromagnetic waves in increasing frequency is radio, infrared, visible, ultraviolet, x-ray and gamma. Option B correctly gives the order as infrared, visible, ultraviolet, and gamma, which is the correct order in terms of increasing frequency. The other options are incorrect and do not follow the correct order of increasing frequency.

Quiz 21: Alternating Current Circuits and Electromagnetic Waves

An electromagnetic wave with a peak magnetic field component of 1.5 x 10^-7 T has an associated peak electric field component of what value? (m₀ = 4p x 10^-7 Tm/A,e₀ = 8.85 x 10^-12 C²/Nm² and c = 3.00 x 10⁸ m/s)

A solar cell has a light-gathering area of 10 cm² and produces 0.20 A at 0.80 V (dc) when illuminated with sunlight of intensity 1 000 W/m².What is the efficiency of the solar cell?

The Earth is 1.49 x 10¹¹m 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?

What is the maximum value of the electric field E at 1.0 m from a 100-W light bulb radiating in all directions? (µ₀ = 4p x 10^-7 T*m/A,c = 3.00 x 10⁸ m/s)

Peak values for a neodymium-glass laser are 600 J for 1 nanosecond.If the cross-section of the laser beam is 1 cm²,what are the maximum values of E and B? (µ₀ = 4p x 10^-7 T*m/A,c = 3.00 x 10⁸ m/s)

Determine the amount of energy carried in l.0 m of a 3.5-mW He-Ne laser beam if the cross-sectional area of the beam is 5.0 x 10^-6 m².

An electromagnetic wave with a peak electric field component of 1.2 x 10² N/C has what associated peak magnetic field value? (e₀ = 8.85 x 10^-12 C²/Nm²,m₀ = 4p x 10^-7 Tm/A and c = 3.00 x 10⁸ m/s)

Which condition of motion must be met with regard to a charged particle if it is in the process of emitting electromagnetic radiation?

A radar pulse returns 3.0 x 10^-4 seconds after it is sent out,having been reflected by an object.What is the distance between the radar antenna and the object? (c = 3.00 x 10⁸ m/s)

An electromagnetic wave with a peak magnetic field component of 1.5 x 10^-7 T carries what average power per unit area? (m₀ = 4p x 10^-7Tm/A,e₀ = 8.85 x 10^-12 C²/Nm² and c = 3.00 x 10⁸ m/s)

A radio wave transmits 1.2 W/m² average power per unit area.What is the peak value of the associated magnetic field? (m₀ = 4p x 10^-7 T*m/A and c = 3.00 x 10⁸ m/s)

In a space lab a 25- sheet of aluminum foil is subjected to a laser beam of intensity on one side and to a beam of intensity on the opposite side,the radiation in each case hitting with normal incidence.What is the net force on the aluminum foil if both sides are considered to be totally reflective?

In order to keep its food hot,a restaurant will place it under which type of lamp?

How is the direction of propagation of an electromagnetic wave oriented relative to the associated and fields?

An electromagnetic wave is made up of which of the following oscillating quantities?

Maxwell guessed that visible light was an electromagnetic wave because of its:

In order of increasing frequency,which of the following is correct?

Quiz 21: Alternating Current Circuits and Electromagnetic Waves

An electromagnetic wave with a peak magnetic field component of 1.5 x 10-7 T has an associated peak electric field component of what value? (m0 = 4p x 10-7 T*m/A,e0 = 8.85 x 10-12 C2/N*m2 and c = 3.00 x 108 m/s)

A solar cell has a light-gathering area of 10 cm2 and produces 0.20 A at 0.80 V (dc) when illuminated with sunlight of intensity 1 000 W/m2.What is the efficiency of the solar cell?

The Earth is 1.49 x 1011 m 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?

What is the maximum value of the electric field E at 1.0 m from a 100-W light bulb radiating in all directions? (µ0 = 4p x 10-7 T*m/A,c = 3.00 x 108 m/s)

Peak values for a neodymium-glass laser are 600 J for 1 nanosecond.If the cross-section of the laser beam is 1 cm2,what are the maximum values of E and B? (µ0 = 4p x 10-7 T*m/A,c = 3.00 x 108 m/s)

Determine the amount of energy carried in l.0 m of a 3.5-mW He-Ne laser beam if the cross-sectional area of the beam is 5.0 x 10-6 m2.

An electromagnetic wave with a peak electric field component of 1.2 x 102 N/C has what associated peak magnetic field value? (e0 = 8.85 x 10-12 C2/N*m2, m0 = 4p x 10-7 T*m/A and c = 3.00 x 108 m/s)